U.S. patent application number 10/870550 was filed with the patent office on 2005-02-03 for system and method for computer based testing using cache and cacheable objects to expand functionality of a test driver application.
Invention is credited to Boone, Doug, Crowhurst, Christopher, Kershaw, Roger C..
Application Number | 20050026130 10/870550 |
Document ID | / |
Family ID | 37003333 |
Filed Date | 2005-02-03 |
United States Patent
Application |
20050026130 |
Kind Code |
A1 |
Crowhurst, Christopher ; et
al. |
February 3, 2005 |
System and method for computer based testing using cache and
cacheable objects to expand functionality of a test driver
application
Abstract
A system and method for computer-based testing includes a test
driver that controls delivery of a computer-based test to one or
more test candidates and that controls caching of test components
during delivery of the test. The system includes various monitoring
components, including monitoring of candidate progress, candidate
performance, network bandwidth, network latency and server
response, during delivery of the test and adjusting the source of
the test components or the volume of the test components being
cached for delivery of the test. Based upon this monitoring of the
system, for example, if network communication failure is detected,
the test candidate is able to continue computer-based testing while
connectivity is being reestablished.
Inventors: |
Crowhurst, Christopher;
(Whitehall, MD) ; Boone, Doug; (Parkton, MD)
; Kershaw, Roger C.; (Melbourne Beach, FL) |
Correspondence
Address: |
ARENT FOX KINTNER PLOTKIN & KAHN
1050 CONNECTICUT AVENUE, N.W.
SUITE 400
WASHINGTON
DC
20036
US
|
Family ID: |
37003333 |
Appl. No.: |
10/870550 |
Filed: |
October 18, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60479952 |
Jun 20, 2003 |
|
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Current U.S.
Class: |
434/362 |
Current CPC
Class: |
H04M 2215/7414 20130101;
H04N 21/2402 20130101; G09B 5/14 20130101; H04M 7/0084 20130101;
G06F 16/9574 20190101; G09B 5/00 20130101; G09B 7/00 20130101; G09B
7/02 20130101; H04N 21/44204 20130101; Y10S 706/927 20130101; G09B
5/06 20130101; H04Q 3/0062 20130101; H04M 15/8016 20130101 |
Class at
Publication: |
434/362 |
International
Class: |
G09B 007/00 |
Claims
What is claimed:
1. A system for computer-based testing comprising: (a) delivery
storage means for storing at least one computer-based test and
delivering over an electronic data network said computer-based test
to at least one test candidate; (b) test driver means for
controlling delivery of said computer-based test from said delivery
storage means; and (c) cache storage means for caching said
computer-based test in response to monitoring of at least one
testing environment variable.
2. The computer-based testing system of claim 1, wherein said
delivery storage means comprises a plurality of test distribution
servers.
3. The computer-based testing system of claim 2, wherein said
plurality of test distribution servers comprises: (a) program
deployment means for storing said test driver means for delivery to
said test candidate; (b) data object deployment means for storing
cacheable data objects of said computer-based test for delivery to
said test candidate; and (c) application object deployment means
for storing cacheable application objects of said computer-based
test for delivery to said test candidate.
4. The computer-based testing system of claim 3, wherein said
cacheable data objects comprise text, multimedia and template
objects.
5. The computer-based testing system of claim 3, wherein said
cacheable application objects comprise plugin program objects.
6. The computer-based testing system of claim 1, wherein said cache
storage means comprises first and second storage means.
7. The computer-based testing system of claim 6, wherein said first
storage means comprises magnetic storage medium.
8. The computer-based testing system of claim 6, wherein said
second storage means comprises random access memory (RAM).
9. The computer-based testing system of claim 1, wherein said test
driver means comprises: (a) a session management component for
administering said computer-based test to said test candidate; (b)
a proctor authentication component for identifying at least one
proctor of said computer-based test; (c) a scheduling component for
verifying test candidate registration for said computer-based test;
(d) a test driver program for controlling delivery of said
computer-based test; (e) a first cache controller for controlling
storing of cacheable data objects in encrypted RAM; (f) a second
cache controller for controlling storing of cacheable application
objects in RAM; and (g) a browser presentation component for
serving said computer-based test to said test candidate.
10. The computer-based testing system of claim 9, wherein said test
driver program comprises: (a) a first request interface for
requesting cacheable data objects; (b) a second request interface
for requesting cacheable application objects; (c) a request
processor for processing requests of said test driver program to
retrieve cacheable data objects and cacheable application objects;
(d) a decryption module for decrypting cacheable data objects and
cacheable application objects; (e) a decompression module for
decompressing cacheable data objects and cacheable application
objects; (f) a first request module for retrieving cacheable data
objects; (g) a second request module for retrieving cacheable
application objects; (h) a first cache for storing retrieved
cacheable data objects; (i) a second cache for storing retrieved
cacheable application objects; (j) a stimuli processor for adapting
delivery of said computer-based test; (k) a cache controller for
controlling source of retrieving cacheable data objects and
cacheable application objects and for controlling volume of
cacheable data objects and cacheable application objects stored in
cache storage means; (l) a network interface for communicating with
a plurality of test distribution servers; and (m) an authentication
component for authenticating cacheable data objects and cacheable
application objects.
11. The computer-based testing system of claim 1, wherein said test
driver means comprises at least one monitoring means for monitoring
a testing environment variable.
12. The computer-based testing system of claim 11, wherein said
monitoring means is a test candidate progress monitor for measuring
progress of said test candidate during computer-based testing.
13. The computer-based testing system of claim 11, wherein said
monitoring means is a test candidate performance monitor for
measuring competency of said test candidate during computer-based
testing.
14. The computer-based testing system of claim 11, wherein said
monitoring means is a network bandwidth monitor for determining a
speed of a network connection through which said computer-based
test is being delivered.
15. The computer-based testing system of claim 11, wherein said
monitoring means is a network state monitor for determining a state
of a network connection through which said computer-based test is
being delivered.
16. The computer-based testing system of claim 11, wherein said
monitoring means is a server state monitor for determining a state
of a server from which said computer-based test is being
delivered.
17. The computer-based testing system of claim 1, wherein said
electronic data network is the Internet.
18. A method for computer-based testing comprising the steps of:
(a) storing at least one computer-based test and delivering over an
electronic data network said computer-based test to at least one
test candidate by delivery storage means; (b) controlling delivery
of said computer-based test from said delivery storage means by
test driver means; and (c) caching and storing said computer-based
test in cache storage means in response to monitoring of at least
one testing environment variable.
19. The method for computer-based testing of claim 18, the method
comprising the step of storing on a plurality of test distribution
servers said computer-based test for delivery to a plurality of
test candidates.
20. The method for computer-based testing of claim 19, the method
comprising the step of storing cacheable data objects comprising
text, multimedia and template objects.
21. The method for computer-based testing of claim 19, the method
comprising the step of storing cacheable application objects
comprising plugin program objects.
22. The method for computer-based testing of claim 19, the method
comprising the step of storing said test driver means in first
storage means comprising magnetic storage medium.
23. The method for computer-based testing of claim 18, the method
comprising the step of storing said cacheable data objects in
second storage means comprising random access memory (RAM).
24. The method for computer-based testing of claim 18, the method
comprising the step of storing said cacheable application objects
in second storage means comprising random access memory (RAM).
25. The method for computer-based testing system of claim 18, the
method comprising the steps of: (a) administering said
computer-based test to said test candidate using a session
management component; (b) identifying at least one proctor of said
computer-based test using a proctor authentication component; (c)
verifying test candidate registration for said computer-based test
using a scheduling component; (d) controlling delivery of said
computer-based test using a test driver program; (e) controlling
storing of cacheable data objects in encrypted RAM using a first
cache controller; (f) controlling storing of cacheable application
objects in RAM using a second cache controller; and (g) serving
said computer-based test to said test candidate using a browser
presentation component.
26. The method of computer-based testing of claim 25, the method
comprising the steps of: (a) requesting cacheable data objects
using a first request interface; (b) requesting cacheable
application objects a second request interface; (c) processing
requests of said test driver program to retrieve cacheable data
objects and cacheable application objects using a request
processor; (d) decrypting cacheable data objects and cacheable
application objects using a decryption module; (e) decompressing
cacheable data objects and cacheable application objects using a
decompression module; (f) retrieving cacheable data objects using a
first request module; (g) retrieving cacheable application objects
using a second request module; (h) storing retrieved cacheable data
objects using a first cache; (i) storing retrieved cacheable
application objects using a second cache; (j) adapting delivery of
said computer-based test using a stimuli processor; (k) controlling
source for retrieval of cacheable data objects and cacheable
application objects and for controlling volume of cacheable data
objects and cacheable application objects stored in cache storage
means using a cache controller; (l) communicating with a plurality
of test distribution servers using a network interface; and (m)
authenticating cacheable data objects and cacheable application
objects using an authentication component.
27. The method of computer-based testing of claim 18, the method
comprising the step of monitoring at least one test environment
variable.
28. The method of computer-based testing of claim 27, the method
comprising the step of monitoring test candidate progress for
measuring progress of said test candidate during computer-based
testing.
29. The method of computer-based testing of claim 27, the method
comprising the step of monitoring test candidate performance for
measuring competency of said test candidate during computer-based
testing.
30. The method of computer-based testing of claim 27, the method
comprising the step of monitoring network bandwidth for determining
a speed of a network connection through which said computer-based
test is being delivered.
31. The method of computer-based testing of claim 27, the method
comprising the step of monitoring network state for determining a
state of a network connection through which said computer-based
test is being delivered.
32. The method of computer-based testing of claim 27, the method
comprising the step of monitoring server state for determining a
state of a server from which said computer-based test is being
delivered.
33. The method for computer-based testing of claim 18, the method
comprising the step of delivering over the Internet said
computer-based test.
34. A computer-readable storage medium for storing a computer-based
testing method, said computer-based testing method comprising: (a)
storing at least one computer-based test on delivery storage means
and delivering over an electronic data network said computer-based
test to at least one test candidate by said delivery storage means;
(b) controlling delivery of said computer-based test from said
delivery storage means by test driver means; and (c) caching and
storing said computer-based test in cache storage means in response
to monitoring of at least one testing environment variable.
35. The storage medium for storing a computer-based testing method
of claim 34, the method comprising the step of storing on a
plurality of test distribution servers said computer-based test for
delivery to a plurality of test candidates.
36. The storage medium for storing a computer-based testing method
of claim 35, the method comprising the step of storing cacheable
data objects comprising text, multimedia and template objects.
37. The storage medium for storing a computer-based testing method
of claim 35, the method comprising the step of storing cacheable
application objects comprising plugin program objects.
38. The storage medium for storing a computer-based testing method
of claim 35, the method comprising the step of storing said test
driver means in first storage means comprising magnetic storage
medium.
39. The storage medium for storing a computer-based testing method
of claim 35, the method comprising the step of storing said
cacheable data objects in second storage means comprising random
access memory (RAM).
40. The storage medium for storing a computer-based testing method
of claim 35, the method comprising the step of storing said
cacheable application objects in second storage means comprising
random access memory (RAM).
41. The storage medium for storing a computer-based testing method
of claim 34, the method comprising the steps of: (a) administering
said computer-based test to said test candidate using a session
management component; (b) identifying at least one proctor of said
computer-based test using a proctor authentication component; (c)
verifying test candidate registration for said computer-based test
using a scheduling component; (d) controlling delivery of said
computer-based test using a test driver program; (e) controlling
storing of cacheable data objects in encrypted RAM using a first
cache controller; (f) controlling storing of cacheable application
objects in RAM using a second cache controller; and (g) serving
said computer-based test to said test candidate using a browser
presentation component.
42. The storage medium for storing a computer-based testing method
of claim 41, the method comprising the steps of: (a) requesting
cacheable data objects using a first request interface; (b)
requesting cacheable application objects a second request
interface; (c) processing requests of said test driver program to
retrieve cacheable data objects and cacheable application objects
using a request processor; (d) decrypting cacheable data objects
and cacheable application objects using a decryption module; (e)
decompressing cacheable data objects and cacheable application
objects using a decompression module; (f) retrieving cacheable data
objects using a first request module; (g) retrieving cacheable
application objects using a second request module; (h) storing
cacheable data objects using a first cache; (i) storing cacheable
application objects using a second cache; (j) adapting delivery of
said computer-based test using a stimuli processor; (k) controlling
source for retrieval of cacheable data objects and cacheable
application objects and for controlling volume of cacheable data
objects and cacheable application objects stored in cache storage
means using a cache controller; (l) communicating with a plurality
of test distribution servers using a network interface; and (m)
authenticating cacheable data objects and cacheable application
objects using an authentication component.
43. The storage medium for storing a computer-based testing method
of claim 34, the method comprising the step of monitoring at least
one test environment variable.
44. The storage medium for storing a computer-based testing method
of claim 43, the method comprising the step of monitoring test
candidate progress for measuring progress of said test candidate
during computer-based testing.
45. The storage medium for storing a computer-based testing method
of claim 43, the method comprising the step of monitoring test
candidate performance for measuring competency of said test
candidate during computer-based testing.
46. The storage medium for storing a computer-based testing method
of claim 43, the method comprising the step of monitoring network
bandwidth for determining a speed of a network connection through
which said computer-based test is being delivered.
47. The storage medium for storing a computer-based testing method
of claim 43, the method comprising the step of monitoring network
state for determining a state of a network connection through which
said computer-based test is being delivered.
48. The storage medium for storing a computer-based testing method
of claim 43, the method comprising the step of monitoring server
state for determining a state of a server from which said
computer-based test is being delivered.
49. The storage medium for storing a computer-based testing method
of claim 43, the method comprising the step of delivering over the
Internet said computer-based test.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to and claims priority from U.S.
Provisional Patent Application No. 60/479,952, filed Jun. 20, 2003,
the disclosure of which is incorporated herein by reference in its
entirety, and is further related to U.S. Patent Publication No.
20030203342, published on Oct. 30, 2003 and entitled "METHOD AND
SYSTEM FOR COMPUTER BASED TESTING USING CUSTOMIZABLE TEMPLATES",
U.S. Patent Publication No. 20030196170, published on Oct. 16, 2003
and entitled "METHOD AND SYSTEM FOR COMPUTER BASED TESTING USING A
NON-DETERMINISTIC EXAM EXTENSIBLE LANGUAGE (XXL) PROTOCOL", U.S.
Patent Publication No. 20030182602, published on Sep. 25, 2003 and
entitled "METHOD AND SYSTEM FOR COMPUTER BASED TESTING USING
PLUGINS TO EXPAND FUNCTIONALITY OF A TEST DRIVER", and U.S. Patent
Publication No. 20030138765, published on Jul. 24, 2003 and
entitled "METHOD AND SYSTEM FOR COMPUTER BASED TESTING USING AN
AMALGAMATED RESOURCE FILE", and U.S. Patent Publication No.
20030129573, published on Jul. 10, 2003 and entitled "EXTENSIBLE
EXAM LANGUAGE (XXL) PROTOCOL FOR COMPUTER BASED TESTING", all of
which were filed concurrently and all of which are incorporated
herein by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is related to systems and methods used
to facilitate computer based testing such as those that utilize
network systems. More particularly, the present invention uses
cacheable objects to expand functionality of a test driver
application. And, even more particularly, such cacheable objects
include cacheable data objects and cacheable program and
application objects that may be used by a test driver application
in facilitating test taking and administration.
[0004] 2. Description of the Related Art
[0005] For many years, standardized testing has been a common
method of assessing examinees as regards educational placement,
skill evaluation, etc. Due to the prevalence and mass distribution
of standardized tests, computer-based testing has emerged as a
superior method for providing standardized tests, guaranteeing
accurate scoring, and ensuring prompt return of test results to
examinees.
[0006] Tests are developed based on the requirements and
particulars of test developers. Typically, test developers employ
psychometricians or statisticians and psychologists to determine
the specific requirements specific to human assessment. These
experts often have their own, unique ideas regarding how a test
should be presented and regarding the necessary contents of that
test, including the visual format of the test as well as the data
content of the test. Therefore, a particular computer-based test
has to be customized to fulfill the client's requirements.
[0007] FIG. 1 illustrates a prior art process for computerized test
customization, denoted generally by reference numeral 10. First, a
client details the desired test requirements and specifications,
step 12. The computerized test publisher then creates the tools
that allow the test publisher to author the items, presentations,
etc., required to fulfill the requirements, step 14. The test
publisher then writes an item viewer, which allows the test
publisher to preview what is being authored, step 16.
[0008] An item presenter is then written to present the new item,
for example, to the test driver, step 18. Presenting the new item
to the test driver requires a modification of the test driver's
executable code. The test driver must be modified so that it is
aware of the new item and can communicate with the new item
presenter, step 20. The test packager must then also be modified,
step 22. The test packager, which may also be a compiler, takes
what the test publisher has created and writes the result as new
object codes for the new syntax. Subsequently, the scoring engine
must also be modified to be able to score the new item type, step
24. Finally, the results processor must be modified to be able to
accept the new results from the new item, step 26. This process
requires no less than seven software creations or modifications to
existing software.
[0009] U.S. Pat. No. 5,827,070 (Kershaw et al.) and U.S. Pat. No.
5,565,316 (Kershaw et al.) are incorporated herein by reference.
The '070 and '316 patents, which have similar specifications,
disclose a computer-based testing system comprising a test
development system and a test delivery system. The test development
system comprises a test document creation system for specifying the
test contents, an item preparation system for computerizing each of
the items in the test, a test preparation system for preparing a
computerized test, and a test packaging system for combining all of
the items and test components into a computerized test package. The
computerized test package is then delivered to authorized examinees
on a workstation by the test delivery system.
[0010] FIGS. 2A and 2B illustrate the test preparation process as
disclosed in the '070 and '316 patents. Test developers assemble
the test as shown at 32. As shown at 36, item selection is
preferably automated (AIS) using the test development/document
creation ("TD/DC") system or an equivalent test document creation
system. Using "TD/DC", test developers enter the test
specifications into the "TD/DC" system. Based on these
specifications, "TD/DC" searches its central database for items,
which satisfy the test specification, e.g., 50 math questions, 25
of which are algebra problems and 25, which are geometry problems.
Then, the test developers review the items selected by "TD/DC" for
sensitivity and overlap constraints described in the background
section. If the test developer decides that the sensitivity or
overlap constraints are not satisfied by the current selection of
items, certain items may be designated to be replaced by another
item from the database. In addition, test developers provide a test
description specifying the directions, messages, timing of
sections, number of sections of the test, etc. as shown at 42. If a
computer adaptive test (CAT) is to be run, test developers may run
a computer adaptive test simulation at 34, which are known to
skilled test developers. Using the Test Preparation Tool (TPT) and
TOOLBOOK 46, the test preparation system ("TPS") prepares the test
level components as shown at 50. TOOLBOOK is commercially available
from Asymetrix Corporation. The test level components include
scripts 66, item table block sets 56, general information screens
58, direction screens 60, message screens 62, and tutorial units
64. Each of the test components will be described in detail below.
As the components are prepared, the TPT stores them in a TPS
network directory 52. Then, the components are entered into the TPS
Production database 54. The components stored in the TPS Production
database 54 will be retrieved during test packaging.
[0011] U.S. Pat. No. 5,513,994 (Kershaw et al.), which is
incorporated herein by reference, discloses a centralized
administrative system and method of administering standardized test
to a plurality of examinees. The administrative system is
implemented on a central administration workstation and at least
one test workstation located in different rooms at a test center.
The administrative system software, which provides substantially
administrative functions, is executed from the central
administration workstation. The administrative system software,
which provides function carried out in connection with a test
session, is executed from the testing workstations.
[0012] However, computer-based testing has expanded from standalone
distribution administered at a local test center to wide area
network distribution administered via clustered servers at multiple
locations. Thus, a distributed computer-based testing system
requires scalability to support continuous exam administration and
a high volume of concurrent test candidates who may be located at
many remote locations.
[0013] Additionally, computer-based tests have evolved from mere
display of simple text-based content to include streaming of audio
and video content. Thus, a distributed computer-based testing
system demands sufficient system resources and storage capacity as
well as efficient data communication management to serve
bandwidth-intensive multimedia content in a consistent manner.
[0014] Moreover, computer-based test models have advanced to
include adaptive and simulation test models. Thus, a distributed
computer-based testing system must support a variety of complex
test models.
[0015] Further, a distributed computer-based testing system must
facilitate a fair testing environment within a dynamic networked
environment to test candidates who may have varying workstation
capabilities or network connectivity. A number of factors affect
the creation and maintenance of a fair testing environment,
including bandwidth mismatches and network latency between a test
candidate workstation and a test distribution server as well as
between a test distribution server and a test source server, the
available system resources of the test source server, the test
distribution servers and the test candidate workstations, and test
component characteristics (e.g., whether the object is text, audio
or video). Thus, it is necessary to monitor candidate progress,
candidate performance, network bandwidth, network latency, and
server response, among other testing environment variables, during
computer-based testing and cache test components in response to
changes in the testing environment in order to ensure timely and
consistent delivery of the computer-based test. In other words, a
distributed computer-based testing system must be adjustable to
emulate a suitable testing environment on test candidate
workstations concurrently executing the same computer-based
test.
SUMMARY OF THE INVENTION
[0016] The present invention discloses a computer-based testing
system that controls delivery of a computer-based test to a high
volume of concurrent test candidates and that adapts delivery of
the computer-based test in response to changes in the testing
environment.
[0017] It is one feature and advantage of the present invention to
deliver computer-based tests to a high volume of concurrent test
candidates located at multiple locations.
[0018] It is another feature and advantage of the present invention
to securely administer computer-based tests among concurrent test
candidates located at multiple locations.
[0019] It is another feature and advantage of the present invention
to monitor candidate progress during computer-based testing for
ensuring that test components are timely available for delivery to
a test candidate during testing.
[0020] It is another feature and advantage of the present invention
to monitor candidate performance during computer-based testing for
ensuring that suitable test components are available for delivery
to a test candidate during testing, for example, to support
Computer Adaptive Testing (CAT).
[0021] It is another feature and advantage of the present invention
to monitor network bandwidth during computer-based testing for
adapting delivery of a computer-based test to a test candidate in
accordance with the network bandwidth.
[0022] It is another feature and advantage of the present invention
to monitor network latency during computer-based testing for
adapting delivery of a computer-based test to a test candidate in
accordance with the network latency.
[0023] It is another feature and advantage of the present invention
to monitor server response during computer-based testing for
adapting delivery of a computer-based test to a test candidate in
accordance with the server response.
[0024] It is another feature and advantage of the present invention
to enable a test candidate to launch a computer-based test on the
candidate's workstation prior to all the test components having
been delivered to the candidate workstation.
[0025] It is another feature and advantage of the present invention
to enable a test candidate to continue computer-based testing when
network connectivity fails during computer-based testing.
[0026] These and other features and advantages of the present
invention are achieved in systems and methods for computer-based
testing including a test driver application that controls delivery
of a computer-based test to a test candidate. Particularly, the
system includes cacheable objects, including cacheable data objects
(test items) and cacheable program and application objects
(plugins), collectively, test components, to expand the
functionality of the test driver application, enabling the test
driver application to control caching of test components in
response to changes in the testing environment during delivery of a
computer-based test to a candidate workstation. The systems and
methods include monitoring candidate progress, candidate
performance, network bandwidth, network latency and server response
during delivery of the computer-based test and adjusting either the
source of test components or the volume of test components being
cached for delivery of the test. Based upon such monitoring, for
example, if network communication failure is detected, the test
candidate is able to continue computer-based testing while
connectivity is being reestablished in the background.
[0027] There has thus been outlined, rather broadly, the more
important features of the invention and the preferred embodiments
in order that the detailed description thereof that follows may be
better understood, and in order that the present contribution to
the art may be better appreciated. There are, of course, additional
features of the invention that will be described hereinafter and
which will form the subject matter of the claims appended
hereto.
[0028] In this respect, before explaining the preferred embodiments
of the invention in detail, it is to be understood that the
invention is not limited in its application to the details of
construction and to the arrangements of the components set forth in
the following description or illustrated in the drawings. The
invention is capable of other embodiments and of being practiced
and carried out in various ways. Also, it is to be understood that
the phraseology and terminology employed herein are for the purpose
of description and should not be regarded as limiting.
[0029] As such, those skilled in the art will appreciate that the
conception, upon which this disclosure is based, may readily be
utilized as a basis for the designing of other structures, methods
and systems for carrying out the several purposes of the present
invention. It is important, therefore, that the claims be regarded
as including such equivalent constructions insofar as they do not
depart from the spirit and scope of the present invention.
[0030] Further, the purpose of the foregoing abstract is to enable
the U.S. Patent and Trademark Office and the public generally, and
especially the scientists, engineers and practitioners in the art
who are not familiar with patent or legal terms or phraseology, to
determine quickly from a cursory inspection the nature and essence
of the technical disclosure of the application. The abstract is
neither intended to define the invention of the application, which
is measured by the claims, nor is it intended to be limiting as to
the scope of the invention in any way.
[0031] These, together with other objects of the invention, along
with the various features of novelty, which characterize the
invention, are pointed out with particularity in the claims annexed
to and forming a part of this disclosure. For a better
understanding of the invention, its operating advantages and the
specific objects attained by its uses, reference should be had to
the accompanying drawings and descriptive matter in which there is
illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a flow diagram of a prior art method of
computerized test customization;
[0033] FIGS. 2A and 2B are block diagrams of a prior art process
for test production;
[0034] FIG. 3 is a schematic diagram of a computer-based testing
system;
[0035] FIG. 4 is a block diagram illustrating different types of
plugins that are used with the computer-based testing system;
[0036] FIG. 5 illustrates various components that comprise an exam
source file;
[0037] FIGS. 6A and 6B are a schematic illustrating the components,
classes, and interfaces that comprise a test definition language
compiler;
[0038] FIG. 7 is a schematic illustrating the components that
comprise a test driver and a test administration system;
[0039] FIGS. 8A and 8B are schematics illustrating the classes and
interfaces that comprise the test driver;
[0040] FIG. 9 illustrating the interfaces that comprise a
structured storage;
[0041] FIGS. 10A and 10B are schematics illustrating the classes
and interfaces that comprise the structure storage and associated
operations;
[0042] FIG. 11 is a block diagram of main storage branches of an
exam resource file;
[0043] FIG. 12 is a block diagram illustrating an exams branch of
the exam resource file;
[0044] FIGS. 13A and 13B are block diagrams illustrating a forms
branch of the exam resource file;
[0045] FIG. 14 is a block diagram illustrating an items branch of
the exam resource file;
[0046] FIG. 15 is a block diagram illustrating a categories branch
of the exam resource file;
[0047] FIG. 16 is a block diagram illustrating a templates branch
of the exam resource file;
[0048] FIG. 17 is a block diagram illustrating a sections branch of
the exam resource file;
[0049] FIG. 18 is a block diagram illustrating a groups branch of
the exam resource file;
[0050] FIGS. 19A, 19B, 19C, and 19D are block diagrams illustrating
an events sub-branch of the groups branch of the exam resource
file;
[0051] FIG. 20 is a block diagram illustrating a plugins branch of
the exam resource file;
[0052] FIG. 21 is a block diagram illustrating a data branch of the
exam resource file;
[0053] FIG. 22 is a block diagram illustrating a formGroups branch
of the exam resource file;
[0054] FIG. 23 is a block diagram illustrating an attributes branch
of the exam resource file;
[0055] FIG. 24 is a block diagram illustrating a scripts branch of
the exam resource file;
[0056] FIG. 25 is a block diagram illustrating a message box branch
of the exam resource file;
[0057] FIGS. 26A, 26B, 26C, and 26D are block diagrams of an exam
instance file;
[0058] FIG. 27 is a flow diagram of a method of computerized test
customization;
[0059] FIG. 28 is a flow chart of a method of test production and
test delivery;
[0060] FIG. 29 is a flow chart of a method for validation of test
specification and content;
[0061] FIG. 30 is a flow chart of a method for test delivery;
[0062] FIG. 31 is a flow chart of a method of restarting a test
after interruption;
[0063] FIG. 32 is a diagram of a life cycle of a plugin;
[0064] FIG. 33 is a flow diagram of a process for compiling
plugins;
[0065] FIGS. 34A, 34B, 34C, and 34D are flow diagrams of a process
for delivering plugins to an examinee during a computer-based
test;
[0066] FIG. 35 is a block diagram illustrating an example of a
network environment for a computer-based testing system according
to the present invention;
[0067] FIG. 36 is a block diagram illustrating a caching
architecture for a computer-based testing system according to the
present invention;
[0068] FIGS. 37A and 37B are flow charts of methods for caching
test components according to the present invention; and
[0069] FIGS. 38A, 38B, 38C, 38D and 38E are flow charts of methods
for monitoring candidate performance, candidate progress, network
latency, network bandwidth and server response according to the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0070] Reference now will be made in detail to the presently
preferred embodiments of the invention. Such embodiments are
provided by way of explanation of the invention, which is not
intended to be limited thereto. In fact, those of ordinary skill in
the art may appreciate upon reading the present specification and
viewing the present drawings that various modifications and
variations can be made.
[0071] For example, features illustrated or described as part of
one embodiment can be used on other embodiments to yield a still
further embodiment. Additionally, certain features may be
interchanged with similar devices or features not mentioned yet
which perform the same or similar functions. It is therefore
intended that such modifications and variations are included within
the totality of the present invention.
[0072] The present invention discloses a system and method of
computer-based testing using a test driver that is, for example,
object-oriented and is architected to dynamically add functionality
through, for example, the use of an expansion module, and
preferably through the use of plugins. The test driver preferably
references component object model servers using standard
interfaces, and uses, for example, class names (that can be an
Active Document) defined in a custom test definition language
entitled extensible exam Language ("XXL") based on extensible
Markup Language ("XML") format to interact with existing
applications while offering the flexibility of allowing development
of new plugins. These new plugins can be customized to a client's
needs without changing the core test driver. The specific format
and protocol of XXL is also described in U.S. Patent Publication
No. 20030129573, published Jul. 10, 2003 and entitled "EXTENSIBLE
EXAM LANGUAGE (XXL) PROTOCOL FOR COMPUTER BASED TESTING",
incorporated herein by reference.
[0073] The plugins advantageously enable the test driver to
support, for example, new item types, navigation algorithms,
information displays, scoring algorithms, timing algorithms, test
unit selection algorithms, results persistence reporting, printed
score reporting, and/or helm types without change to the test
driver's executable. Plugins also allow expansion of the test
driver's functionality without requiring the test driver to be
recompiled or re-linked, and without requiring the test publisher
to learn to program. Since plugins are written independently of the
test driver, plugins can be written long after the test driver is
built. The client and the software developer can design and test
the plugins and distribute the plugins to each test site. By using
this method, large-scale regression testing of other examinations
will not usually be necessary unless changes are made to the
plugins that may be used by many examinations. The specific use of
plugins is described in U.S. Patent Publication No. 20030182602,
published Sep. 25, 2003 and entitled "METHOD AND SYSTEM FOR
COMPUTER BASED TESTING USING PLUGINS TO EXPAND FUNCTIONALITY OF A
TEST DRIVER", incorporated herein by reference.
[0074] The test driver of the present invention controls delivery
of a computer-based test to a test candidate, including controlling
caching of test components during delivery of the test. In
accordance to monitoring of the testing environment, including
monitoring candidate progress, candidate performance, network
bandwidth, network latency and server response, during delivery of
the test, the test driver adjusts either the source of test
components or the volume of test components being cached for
delivery of the test. Based on such monitoring, for example, if
network communication failure is detected, the test candidate is
able to continue computer-based testing while connectivity is being
reestablished in the background. By using this system, a uniform
testing environment can be established and maintained during
computer-based testing in a distributed computer-based testing
environment.
[0075] I. Overview of Computer-Based Test Delivery System
[0076] FIG. 3 shows an overview of the software architecture for
the computer-based test delivery system of the present invention,
denoted generally by reference numeral 100. Test driver 110 is
responsible for controlling all aspects of the computer-based test.
Test driver 110 identifies candidates scheduled to take the
computer-based test and identifies and creates the appropriate
test. Test driver 110 then presents all of the test components to
candidates using a display device (not shown), such as a computer
monitor, and enables candidates to enter responses to test
questions through the use of an input device (not shown), such as a
keyboard, a mouse, etc. Test driver 110 also monitors the security
of the test. For example, test driver 110 can prevent access to the
Internet and can validate candidates, although, these functions are
preferably performed by the test center administration system. Test
driver 110 also monitors the timing of the test, providing relevant
warnings to candidate regarding the elapsed time of the test and
the time remaining for a particular section of the test or for the
entire test. Test driver 110 is also responsible for scoring the
test, once the test is completed or while the test is in progress,
and for reporting the results of the test by physical printout
using printer 182 or in a file format using candidate exam results
file 180. If the test is interrupted while in progress, for
example, due to a power failure, test driver 110 restarts the test,
preferably at the point at which the test was interrupted, as will
be described subsequently in more detail. Finally, if the test is
left incomplete, test driver 110 cleans up the incomplete test. An
incomplete test will have an exam instance file in the candidate's
directory but will not have created a results file. A results file
is created even though generally the candidate will fail. The
number of items delivered to the candidate is recorded in the
results file. Test driver 110 picks up where the event was
interrupted and invisibly delivers the rest of the units of the
test.
[0077] A test specification is authored by a test publisher
according to the specifications of the client and stored in exam
source files 130. Exam source files 130 include data files 132, XXL
files 134, multimedia files 136, and hypertext markup language
("HTML") files 138. XXL files 134 include the test specification,
which contains the client's requirements for the test, a bank of
test items or questions, templates that determine the physical
appearance of the test, plugins, and any additional data necessary
to implement the test. Additional data is also stored in data files
132. For example an adaptive selection plugin may need a, b & c
theta values. These values are stored in a binary file created by a
statistical package.
[0078] HTML files 130 include, for example, any visual components
of the test, such as the appearance of test items or questions, the
appearance of presentations on the display device, the appearance
of any client specified customizations, and/or the appearance of
score reports. HTML files 130 preferably also include script, for
example, VBscript and Jscript, or Java script. HTML files 130 are
preferably authored using Microsoft's FrontPage 2000. FrontPage
2000 is preferably also used to manage the source files in a
hierarchy that is chosen by the test publisher. Multimedia files
136 include, for example, any images (.jpg, .gif, etc.) and/or
sound files (.mp3, .wav, .au, etc.) that are used during the
test.
[0079] XXL compiler 140 retrieves XXL files 134 from exam source
files 130 using interface 190 and compiles the XXL test content
stored in XXL files 134. XXL compiler 140 stores the compiled test
files in exam resource file 120. In another embodiment, exam source
files 130 do not contain XXL files 134 and contains, for example,
only multi-media files. In this embodiment, XXL compiler 140 is
merely a test packager that writes the data directly to exam
resource file 120 without modification or validation. The data
appears in a stream under the "data" branch of exam resource file
120. The name of the stream is specified by the test author.
[0080] In a preferred embodiment, XXL files 134 also include XXL
language that defines plugins 150, in which case, plugins 150
assist XXL compiler 140 in compiling XXL files 134. Test driver 110
preferably supports, for example, nine different types of plugins
150, including, for example: display plugin 152; helm plugin 154;
item plugin 156; timer plugin 158; selection plugin 160; navigation
plugin 162; scoring plugin 164; results plugin 166; and report
plugin 168. Plugins 150, which are also included in XXL files 134,
are the first XML files compiled into exam resource file 120.
[0081] Plugins 150 allow a test designer to customize the behavior
of test driver 110 and are divided into two types, for example:
visible plugins and invisible plugins, as shown in FIG. 4. The
visible plugins, which include display plugin 152, helm plugin 154,
and item plugin 156, enable the test driver to control what is
presented visually to an candidate on the display device. The
invisible plugins, which include timer plugin 158, selection plugin
160, navigation plugin 162, scoring plugin 164, results plugin 166,
and report plugin 168, enable the test driver to control more
functional aspects of the test. Plugins 150 are used to validate
data stored in exam source files 130 that is to be used by one of
plugins 150 during delivery of the test to the candidate, as is
described below in greater detail. Plugins 150 are, preferably,
component object model ("COM") objects, as described below. Plugins
150, may also utilize Java implementation. Plugins 150 are
preferably written using Microsoft Visual C++ or Visual Basic 6.0
or any fully COM enabled language. Plugins 150 may be in or
out-of-process, and, therefore, can exist as executable (".EXE")
files or as dynamic link library (".DLL") files.
[0082] An application or component that uses objects provided by
another component is called a client. Components are characterized
by their location relative to clients. An out-of process component
is an .exe file that runs in its own process, with its own thread
of execution. Communication between a client and an out-of-process
component is therefore called cross-process or out-of-process
communication.
[0083] An in-process component, such as a .dll or .ocx file, runs
in the same process as the client. It provides the fastest way of
accessing objects, because property and method calls don't have to
be marshaled across process boundaries. However, an in-process
component must use the client's thread of execution.
[0084] Exam resource file 120 receives the compiled test content
from XXL compiler 140 and plugins 150, if applicable, and stores
the compiled test content in an object-linking and embedding
("OLE") structured storage format, called POLESS, which is
described in greater detail below. Other storage formats may
optionally be used. OLE allows different objects to write
information into the same file, for example, embedding an Excel
spreadsheet inside a Word document. OLE supports two types of
structures, embedding and linking. In OLE embedding, the Word
document of the example is a container application and the Excel
spreadsheet is an embedded object. The container application
contains a copy of the embedded object, and changes made to the
embedded object affect only the container application. In OLE
linking, the Word document of the example is the container
application and the Excel spreadsheet is a linked object. The
container application contains a pointer to the linked object and
any changes made to the linked object change the original linked
object. Any other applications that link to the linked object are
also updated. POLESS supports structured storage such that only one
change made to an object stored in exam resource file 120 is
globally effective. Test driver 110 comprises Active Document
container application 112 for the visible plugins, display plugin
152, helm plugin 154, and item plugin 156, which function as
embedded objects, preferably COM objects.
[0085] Both XXL compiler 140 and plugins 150 are involved in
storing the compiled test content into exam resource file 120, if
any of plugins 150 are being used. Exam resource file 120
comprises, for example, a hierarchical storage structure, as will
be described in further detail below. Other storage structures may
optionally be used. XXL compiler 140 determines to which storage
location a specific segment of the compiled test content is to be
stored. However, if any of plugins 150 are used to validate the
portion of any of the data from exam source files 130, then the
plugins 150 store the data directly to the exam resource file,
based upon directions from XXL compiler 140. XXL compiler uses
IPersistResource interface 192, co-located with I-Plugin interface
167 in FIG. 3, to control the persistence of the data to exam
resource file 120. XXL compiler 140 and plugins 150 write the data
to exam resource file 120 using POLESS interfaces 191.
[0086] FIG. 5 illustrates the contents of exam source file 130,
which are compiled into exam resource file 120 by XXL compiler 140
and plugins 150. FrontPage 2000 Web 200 is used, for example, to
author the test. Exam source files 130 contain media files 210,
visual files 220, and logic files 230. Media files 210 are
multimedia files used to enhance the presentation of the test,
including, for example, XML data files 212, sound files 214, image
files 216, and binary files 218. XML data files 212 include the XXL
test definition language and the XXL extensions from the plugins
150 that use XML. The test specification, presentation, scoring and
other information is specified in the XML files. Sound files 214
include any sounds that are to be used during the test, such as
.mp3 files, .au files, etc. Image files 216 include any images to
be used during the test, such as .jpg files, gif files, etc. Binary
files 218 include any data needed by a plugin 150 that is not in
XXL format. Visual files 220 are HTML files that specify the visual
presentation of the test as presented to the examine on the display
device, including items files 222, presentation files 224, score
report files 226, and custom look files 228. Items files 222
include HTML files that are used to specify the visual component of
test questions, e.g., stems and distractors. Items files 222 are
capable also of referencing external exhibits. An exhibit could be
a chart, diagram or photograph. Formats of exhibits include, for
example: .jpg, .png, etc. Presentation files 224 define what is
seen by the candidate on the display device at a particular instant
during the test. Score report files 226 is typically an HTML file
with embedded script that includes, for example candidate
demographics, appointment information, and candidate performance.
The performance might include pass/fail, achievement in different
content areas, etc. Custom look files 228 are typically HTML files
with embedded script to layout, for example, the title bar and
information contained therein. Logic files 230 are XML files that
specify the functional aspects of the test, including test
specification files 232, plugin files 234, item bank files 236, and
template files 238. Test specification files 232 specify the
content and progress of the test as provided by the client. Plugin
files 234 define plugins 150 and contain any data necessary to
implement plugins 150. Item bank files 236 include the data content
and properties of the items, or test questions, that are to be
presented to the candidate during the test. Properties of an item
include the correct answer for the item, the weight given to the
item, etc. Template files 238 define visual layouts that are used
with the display screen during the test.
[0087] Referring again to FIG. 3, once a test has begun, test
driver 110 accesses exam resource file 120 for the instructions and
files needed to implement the test, using POLESS interfaces 193.
Test driver 110 also accesses plugins 150 for additional data that
expands the functionality of test driver 110 in the areas of items,
navigation algorithms, information displays, scoring algorithms,
timing algorithms, test unit selection algorithms, results
persistence reporting, printed score reporting, and/or helm types.
Test driver 110 communicates with plugins 150 using various COM
interfaces 169. COM interfaces facilitate OLE linking. As stated
previously, test driver 110 is an Active Document container
application and plugins 150 are embedded objects. The COM
interfaces function as communications paths between the container
application and the objects.
[0088] There are, for example, ten COM interfaces utilized in
computer-based test delivery system 100. IPlugin interface 167,
which is also a COM interface, is supported by all of plugins 150.
COM interfaces 169, therefore, includes the IPlugin interface. The
IPlugin interface contains generic operations such as loading and
unloading, required of all plugins 150. In addition to the global
IPlugin interface, each plugin 150 also uses, for example, a
second, individual COM interface 169 to communicate with test
driver 110. Alternative structures of the IPlugin interface may
also be used. Table 1 shows the relationship between each plugin
150 and the COM interface 169 used with that particular plugin
150.
1TABLE 1 COM INTERFACE FOR PLUGINS. PLUGIN COM INTERFACE
DESCRIPTION All Plugins 150 IPlugin Passes data between the test
driver and all plugins regarding generic operations, e.g., loading
and unloading. Display 152 IDisplay Passes data between the test
driver and the visible plugins that handle title bars, displays,
non- answered items, and summaries. Helm 154 IHelm Passes data
between the test driver and the visible plugins that display
navigation controls or reviews. Communicates with a navigation
plugin to perform the actual navigation. Also functions as a user
interface connection to the test driver. Item 156 IItem Passes data
between the test driver and the visible plugins that govern test
items or simulations. Timer 158 IUnitTimer Passes data between the
test drivers and the invisible plugins used to perform timing
across examination sections. Selection 160 ISelection Passes data
between the test drivers and the invisible plugins used to select
forms, sections, groups, or items for delivery to the candidate.
Navigation 160 INavigate Passes data between the test drivers and
the invisible plugins used to control section navigation and define
rules for traversing through the test. Scoring 164 IScore Passes
data between the test drivers and the invisible plugins used to
control scoring of delivered testing units. Results 166 IResults
Passes data between the test drivers and the invisible plugins that
control writing of candidate results, for example, to candidate
exam results file 180. Report 168 IReport Passes data between the
test drivers and the invisible plugins that control printing of
score reports and other material, for example, printed reference
material and post exam instructions to printer 182.
[0089] Exam instance file 170 is used to restart a test if the test
has been interrupted, for example, because of a power failure.
During delivery of the test, exam instance file 170 receives
examination state information from test driver 110 and plugins 150
regarding the state of all running objects being used to deliver
the test. The examination state information includes the
presentation that was being delivered on the display device before
the interruption, the responses the candidate had entered in that
presentation, etc. When the test is restarted, the exam instance
file 170 loads the state information back to test driver 110 and
plugins 150, allowing the test to return to operation at the point
where the test had been interrupted. Preferably, the running state
of all objects is saved to exam instance file 170 rather than of
only some of the objects. Saving the state of only some of the
objects to exam instance file 170 causes the potential problem of
only a portion of the test information being restored after a test
interruption. Exam instance file 170 may also store additional
information relating to the test, including, for example: the
timing utilized and time remaining on units of the exam, the
current unit of delivery, candidate score, etc. Test driver 110 and
plugins 150 communicate with exam instance file 170 using POLESS
interfaces 195. Test driver 110 controls communications between
test driver 110 and plugins 150 using IPersistInstance interface
196, which is collocated with COM interfaces 169 in FIG. 3.
[0090] Several administrative environments perform the
administrative functions of computer-based test delivery system
100, for example: Test Center Manager ("TCM") Bridge 172;
Educational Testing Service ("ETS") Bridge 174; and Unified
Administration System ("UAS") 174. Administrative functions
include, for example: checking-in an candidate, starting the test,
aborting the test, pausing the test, resuming the test, and
transmitting results.
[0091] There are preferably two ways to run test driver 110. The
first is through a series of command line options and the second is
using COM interfaces describing appointment information. The
command line option exists for backwards compatibility in a
standard ETS environment and a TCM environment. Table 2 shows a
list of command line options test driver 110 supports. There are,
for example, four programs which launch the test through the COM
interface, for example: 1) LaunchTest.exe (for test production and
client review); 2) UAS; 3) UTD2ETS.dll (an internal compatibility
module for use with the ETS administration environment); and 4)
UTD2TCM (for the Test Center Manger environment). Other number of
environments and/or programs may optionally be used.
2TABLE 2 COMMAND LINE OPTIONS SUPPORT BY TEST DRIVER. SWITCH (ES)
OPTION(S) PURPOSE /? n/a Displays command line /help switches in
dialog box. /UnregServer n/a Unregisters the test driver core COM
server. /RegServer n/a Registers the test driver core COM server.
/T Form name Name of the form or form group to run in the exam. /F
Resource file The exam resource file to use. /S n/a Suppress any
printing. /W n/a Run in close-of-day mode. /TI n/a Set tracing
level to information. (Very large instance file). /TW n/a Set
tracing level to warning. (Large instance file.) /TE n/a Set
tracing level to error. (Average sized instance file.) /K Resource
dir, Used to point to SKSID, candidate directories. A space
director separates each of the three options.
[0092] The administration environments use several interfaces to
communicate with test driver 110. IAppointment interface 176 is
part of UAS 174 and allows access by test driver 110 to candidate
information for the candidate taking the test, such as
demographics. The candidate information is included in candidate
exam results file 180, which is created by the test driver.
ILaunch2 interface 177 functions as the primary control interface
for UAS 174 and allows UAS 174 to control various components such
as test driver 110, screen resolution change, accommodations for
disabled candidates, candidate check-in, etc., in a test center,
which is the physical location where the candidate is taking the
test. ITransfer interface 199 transfers candidate exam results file
180 and other files back to UAS 174. IPrint interface 198 sends
information regarding any reports to printer 182.
[0093] The test driver is described in greater detail in U.S.
Patent Publication No. 20030182602, entitled "METHOD AND SYSTEM FOR
COMPUTER BASED TESTING USING PLUGINS TO EXPAND FUNCTIONALITY OF A
TEST DRIVER", incorporated herein by reference.
[0094] II. XXL Compiler Interfaces and Classes
[0095] FIGS. 6A and 6B illustrate the main diagram for XXL compiler
140. XXL compiler 140 comprises the following classes, for example:
cCompile 2000; cData 2004; cArea 2006; cTemplate 2008; cCategory
2010; cItem 2012; cPresentation 2014; cGroup 2016; cSection 2018;
cForm 2020; cFromGroup 2022; cExam 2024; cMsgBox 2026; cChecksum
2028; cEvent 2030; cResult 2032; cReport 2024; cPlugin 2036; and
cXXL 2038.
[0096] The main interface to XXL compiler 140 is ICompile interface
2002. ICompile interface 2002 is implemented by cCompiler class
2000. All control and initiation of compilation of exam source
files 130 into exam resource file 120 occurs by way of this single
public interface. The core, non-plugin related elements of the XXL
test definition language, as stored in XXL files 134, are compiled
by classes in XXL compiler 140. For example, cSection class 2018,
compiles the section element, and cGroup class 2016 compiles the
group element.
[0097] ICompile interface 2002 supports the following operations,
for example: createResource( ); addSource( ); addData( );
closeResource( ); about( ); linkResource( ); openResource( ) and
getCryptoObject( ). CreateResource( ) creates a resource file, for
example, an XXL based resource file such as exam resource file 120.
AddSource( ) compiles an XXL file into the resource file. AddData(
) adds a file directly to a data branch of the resource file.
CloseResource( ) closes the resource file. LinkResource( ) links a
resource in the resource file and is performed after all compiling
of the source files are completed. GetCryptoObject( ) returns an
ICrypto object containing the current encryption setting of POLESS,
as described below.
[0098] The classes of XXL compiler 1040, e.g., cForm 2020 and cItem
2012, handle individual XXL core language elements. All of these
classes compile the specific XXL source element into exam resource
file 120. All of these class language elements are also symbols
used in later references. Therefore, the classes all derive from
cSymbol class 2040. cSymbol class 2040 allows the classes of XXL
compiler 140 to reside in a symbol table.
[0099] For example, the XXL element plugin 150 appears as follows
in XXL files 134:
3 3 <plugin name="helmNextPrevious" progid="UTDP.cNextPrevious"
/>
[0100] This XXL call causes an instance of cPlugin class 2036 to be
created, compiles the source, and writes the compiled result to
exam resource file 120. The name and ID of Plugin 150 is also added
to the symbol table for later reference.
[0101] XXL compiler 140 also contains the following token classes,
for example: cToken 2042; cTokenCreator NoRef 2044; cTokenCreator
2046; ctokenCreatorRef 2048; cTokenCreatorBase 2050; and
cTokenFactory 2054. These token classes are involved in the
identification of tokens. Tokens turn into symbols after
identification. Symbols are any class derived from cSymbol, e.g.,
cTemplate, cSection, etc.
[0102] XXL compiler 140 also contains the following symbol table
classes, for example: cPluginSymbolTable 2058; cTemplateSymbolTable
2060; cSymbolTable 2062; cFFGSymbolTable 2064; cSGPSymbolTable
2066; and cSymbolTableBase 2068. These classes are varieties of
symbol tables. There are different symbol tables for different
groups of symbols. A group of symbols define a name space for the
symbol. Common symbol table functions are located in the base
symbol table classes and templates.
[0103] All content and specification destined for a plugin 150
appears in the data element in XXL. For example, below is an item
definition in XXL:
4 4 <item name="wantABreak1" skipAllowed="false">
<data> <multiChoice correctAnswer="A" maxResponses="1"
minResponses="1" autoPrompt="false"
URI="itembank/info_item.htm#wantABreak"/>- ; </data>
</item>
[0104] The item element is handled by a cItem class 2012 object.
The data element in the XXL definition is handled by a cData class
2004 object. Item plugin 156 Plugin 150 will receive the source to
compile from the cData class 2004 object, in this example, a
multiChoice element.
[0105] cWrapXML class 2052, a wrapper class for XML DOM nodes,
supports error handling. cCustomAttributes class 2056 compiles the
custom attributes XXL element. cWrapPropertySet class 2070 is a
wrapper class for a POLESS property storage.
[0106] III. Test Driver Interfaces and Classes
[0107] A. Interfaces
[0108] FIG. 7 shows test driver 110, UAS 174, and the interfaces
used by and between the test driver 110 and UAS 174 to deliver the
test. UAS 174 defines ILaunch2 interface 177, which is used by UAS
174 to initiate test events. ILaunch2 interface 177 is an extension
of ILaunch interface 178, which, in other embodiments of the
present invention, is also used by UAS 174 to initiate test events.
UAS 174 also defines and implements additional interfaces, for
example: IAppointment interface 176; IPrint interface 198; and
ITransfer interface 199. IAppointment interface 176 transfers
examinee candidate information and appointment details from UAS 174
to test driver 110, as is illustrated by the dashed arrow
connecting IAppointment interface 176 to test driver 110. IPrint
interface 198 allows UAS 174 to send print requests to printer 198
regarding reports, for example, score reports. ITransfer interface
199 allows UAS 174 to request the transfer of information from
candidate exam results file 180 back to UAS 174.
[0109] Test driver 110 defines various interfaces to allow test
driver 110 to communicate with different parts of computer-based
test delivery system 100. Test driver 110 includes, for example,
ten COM interfaces 169 to communicate and transfer data with
plugins 150. (See Table 1 above) The COM interfaces 169 are denoted
in FIG. 7 as follows, for example: IDisplay interface 169a; IHelm
interface 169b; IItem interface 169c; IUnitTimer interface 169d;
ISelection interface 169e; INavigate interface 169f; IScore
interface 169g; IResults interface 169h; IReport interface 169i;
and IPlugin interface 169j.
[0110] Test driver 110 and plugins 150 communicate and transfer
data with exam resource file 120 using, for example, three
IPersistResource interfaces 192: IPersistResourceStream interface
192a; IPersistResourceSet interface 192b; and IPersistResourceStore
interface 192. IPersistResource interfaces 192 are used by plugins
150 during compilation of exam source files 130 and are used by
both test driver 110 and plugins 150 during delivery of the test.
During compilation of exam source files 130, XXL compiler 140
directs plugins 150 in which storage location of exam resource file
120 to store any information that plugins 150 have validated.
Plugins 150 can then retrieve the stored information from exam
resource file 150 during delivery of the test. Other number of
interfaces and different combination of functionality may
alternatively be used.
[0111] Information is saved from plugins 150, or from XXL compiler
140 in general, to exam resource file 120, for example, as either a
stream of data, as a set of data, or as a storage structure,
depending on which of the three IPersistResource interfaces 192 is
implemented to save the information from plugins 150, to exam
resource file 120. IPersistResourceStream interface 192a saves the
information, for example, as a stream of data or other data storage
format. A stream of data is simply a stream of bytes stored as a
linear sequence. IPersistResourceSet interface 192b saves the
information, for example, as a set of data. A set of data is
preferably a name-value property pair. For example, the name of a
particular property for an item is distractors and the value is the
number of distractors required for that item. IPersistResourceSet
interface 192 allows the name-value property pair to be saved
together in exam resource file 120. IPersistResourceStore interface
192c saves the information, for example, in a directory format with
storage areas. The directory format allows other streams of data to
be saved within the storage area, other property sets to be stored
within the storage area, and for sub-storages to be saved under the
storage area.
[0112] IPersistInstance interface 196, likewise, comprises, for
example, three, different interfaces, for example:
IPersistInstanceStream interface 196a; IPersistInstanceSet
interface 196b; and IPersistInstanceStore interface 196c.
Examination state information is saved to exam instance file 170
as, for example, a stream of data, as a set of data, or as a
storage element, depending on which of the three IPersistResource
interfaces 192 is implemented.
[0113] Two of the interfaces, IContainerNotify interface 200 and
IContainerNotifyHelm interface 206, function as callback interfaces
from plugins 150 to test driver 110. IContainerNotify interface 200
allows a visible plugin to inform test driver 110, for example,
that the plugin is displayed and ready for examinee interaction.
IContainerNotifyHelm interface 206 allows helm plugin 154 to
request navigation from test driver 110 after receiving an input
from the examinee to move to another section of the test. IMore
interface 202 is used to convey whether the examinee has seen all
content in a presentation. For example, a "more" button appears in
place of the next button when the content exceeds the window
length. When the examinee scrolls to the bottom, the "more" button
disappears and is replaced with the "next" button. Collection
interface 204 is used by test driver 110 to hold any group
entities, for example, categories and sections of the test.
[0114] The remaining interfaces are, for example, Microsoft defined
Active Document interfaces, used to implement OLE linking functions
of test driver 110 and the visible plugins, display plugin 152,
helm plugin 154, and item plugin 156. IOleInPlaceFrame interface
210 controls the container's top-level frame window, which involves
allowing the container to insert its menu group into the composite
menu, install the composite menu into the appropriate window frame,
and remove the container's menu elements from the composite menu.
IOleInPlaceFrame interface 210 sets and displays status text
relevant to the end-place object. IOleInPlaceFrame interface 210
also enables or disables the frames modeless dialogue boxes, and
translates accelerator key strokes intended for the container's
frame. IOleInPlaceUI window interface 211 is implemented by
container applications and used by object applications to negotiate
boarder space on the document or frame window. The container
provides a RECT structure in which the object can place toolbars
and other similar controls, determine if tools can in fact be
installed around the objects' window frame, allocates space for the
boarder, and establishes a communication channel between the object
and each frame and document window. IAdviseSync interface 212
enables containers and other objects to receive notifications of
data changes, view changes, and compound-document changes occurring
in objects of interest. Container applications, for example,
require such notifications to keep cached presentations of their
linked and embedded objects up-to-date.
[0115] Calls to IAdviseSync interface 212 methods are a
synchronous, so the call is sent and then the next instruction is
executed without waiting for the calls return. IOleWindow interface
213 provides methods that allow an application to obtain the handle
to the various windows that participate in-place activation, and
also to enter and exit context-sensitive help mode. IOleInPlaceSite
interface 214 manages interaction between the container and the
objects in-place client site. The client site is the display site
for embedded objects, and provides position and conceptual
information about the object. IOleClientSite interface 215 is the
primary means by which an embedded object obtains information about
the location and extent of its display site, its moniker, its user
interface, and other resources provided by its container. Test
driver 110 called IOleClientSite interface 215 to request services
from the container. A container must provide one instance of
IOleClientSite interface 215 for every compound-document it
contains. IOleDocumentSite interface 216 enables a document that
has been implemented as a document object to bypass the normal
activation sequence for in-place-active objects and to directly
instruct its client site to activate it as a document object. A
client site with this ability is called a "document site".
[0116] B. Core Classes
[0117] FIGS. 8A and 8B illustrate the main classes of test driver
110 and the interfaces between test driver 110 and plugins 150.
Also shown are the classes that interface to UAS 174. ITransfer
interface 199, IPrint interface 198, ILaunch2 interface 177, and
IAppointment interface 176 represent the connections from test
driver 110 to UAS 174, as described previously. Some of the lines
depicted in FIG. 8 are solid and some are dashed. The solid lines,
for example, between IcResults interface 240 and cEvent class 252,
represent inheritance. The dashed lines, for example, between IExam
interface 222 and IPlugin interface 169j, represent
instantiation.
[0118] Inheritance, or generalization, relates to a generalized
relationship between classes that shows that the subclass shares
the structure or behavior defined in one or more superclasses. A
generalized relationship is a solid line with an arrowhead pointing
to the superclass. Instantiation, or dependency, represents a
relationship between two classes, or between a class and an
interface, to show that the client class depends on the supplier
class/interface to provide certain services. The arrowhead points
to the supplier class/interface. Some services from a supplier
class to a client class include, for example: the client class
access a value (constant or variable) defined in the supplier
class/interface; methods of the line class invoke methods of the
supplier class/interface; and methods of the client class have
signatures whose return class or arguments are instances of the
supplier class/interface. For instantiation, the cardinality of the
relationship is illustrated in FIG. 8 if the relationship
represents containment. Cardinality specifies how many instances of
one class may be associated with a single instance of another
class. Cardinality can be shown for relationships to indicate the
number of links allowed between one instance of a class and the
instances of another class.
[0119] Test driver 110 also has several interfaces and implementing
classes. Test driver 110 interfaces include, for example: IExam
interface 222; IMsgBox interface 224; ICategory interface 232;
IForm interface 238; IcResults interface 240; IcReport interface
242; IScript interface 246; ISection interface 250; IPresentation
interface 248; and/or IcItem interface 256. The classes that
implement the main interfaces include, for example: cScreenMinimum
class 226; cFormGroup class 228; cPlugin class 230; cArea class
234; cTemplate class 236; cActivePlugin class 250; and cEvent class
252. The interfaces that are prefaced by "Ic" have names that
already exist for plugins 150 to enact, for example, item plugin
156 implements IItem interface 169c. IcItem interface 256, however,
is the interface implemented by test driver 110 class citem (not
shown). Of course, any number of interfaces may be used, depending
on the necessary functionality.
[0120] The core class cExam (not shown) implements ILaunch2
interface 177 so that UAS 174 can control test driver 110. The
appointment object, which implements IAppointment interface 176, is
the main object UAS 174 supplies to test driver 110. The
appointment object is available to plugins 150 by way of IPlugin
interface 169j. Furthermore, all plugins 150 get (IExam) using the
IPlugin interface 169, also.
[0121] The cExam class selects and delivers the form, using
cFormGroup class 228 and IForm interface 238. The form delivers
results using IcResults interface 240, reports using IcReport
interface 242, and sections contained with in the test using
ISection interface 250. Classes that are in the test delivery chain
preferably derive from cEvent class 252.
[0122] The cResults class (not shown) delivers a results plugin 166
that implements IResult interface 169i. The cReport class (not
shown) delivers a report plugin 168 that implements IReport
interface 169h. The cSection, cGroup, and cForm classes (not shown)
use several invisible plugins 150 to control the delivery of the
test. These plugins 150 are timer plugins 158, which implement
IUnitTimer interface 169d, selection plugins 160, which implement
ISelection interface 169e, scoring plugins 164, which implement
IScore interface 169g, and navigation plugins 162, which implement
INavigate interface 169f. The cPresentation class (not shown)
supplies data to its template for the display of the presentation.
The three visible plugins 150 are created and controlled through
cTemplate class 236 and child objects cArea class 234. Item plugins
156 have an extension class in the cItem class (not shown) that
wraps the item plugin 156 and provides generic extended services
that all item plugins 156 implements. The cItem class in test
driver 110 is a wrapper class. The cItem class provides two base
services, for example: generic item functionality and access to
item plugin 156, which is the wrapping function. Item generic
functionality includes, for example: having an item name, having an
item title, determining if the item is scored or un-scored,
determining whether the item has been presented to the examinee,
etc. These services are generic to all items and are provided by
test driver 110. Item plugins 156 perform the actual scoring of the
item, which is unique to each item type. Item plugins 156 present
the content of the item and allow the examinee to interact with the
item. These services are unique to each item type.
[0123] In addition to the interfaces described previously, test
driver 110 implements IRegistry interface 220, which allows VB code
to access the Windows registry. Test driver 110 also implements
ILegacyItem interface 258 and ILegacyScore interface 260, which are
defined by test driver 110 and are implements by certain item
plugins 156 and scoring plugins 164. ILegacyItem interface 258 and
ILegacyScore interface 260 allow old item types that existed in
previous test drivers to report results like the previous test
drivers. For some tests, test driver 110 must report results for
old item types, which had very specific ways of reporting results.
ILegacyItem interface 258 and ILegacyScore interface 260 allow the
new item plugins 156 that represent old item types to report this
legacy format of information to result plugins 166 trying to
imitate previous test drivers.
[0124] A complete description of test driver 110 classes and
interfaces is included in Appendix A.
[0125] IV. POLESS
[0126] All persistent storages, exam resource file 120 and exam
instance file 170, preferably utilize POLESS. POLESS allows data to
be embedded, linked, or references as external files from the
persistent storage to test driver 110 and Active Document container
application 112 (FIG. 3). POLESS supports a hierarchical tree
structure with node or branch level additions, replacements, and
deletions. POLESS also supports optional data encryption at the
node level. The type of encryption employed depends on the
destination of the information in the persistent storage. For
example, different encryption keys may optionally be used for data
being routed to test centers, data being routed to administrative
data centers, and data being routed for client use (e.g., client
review). Microsoft Crypto-API is preferably used to perform
encryption of data in the persistent storage. Finally, POLESS also
supports optional compression at the node level, preferably using
Lempal-Zev compression.
[0127] POLESS is an extension of OLE structured storage compound
document implementation. A compound document is a single document
that contains a combination of data structures such as text,
graphics, spreadsheets, sound and video clips. The document may
embed the additional data types or reference external files by
pointers of some kind. There are several benefits to structured
storage. Structured storage provides file and data persistence by
treating a single file as a structured collection of objects known
as storage elements and streams. Another benefit is incremental
access. If test driver 110 or plugins 150 need access to an object
within a compound file, only that particular object need be loaded
and saved, rather than the entire file. Additionally, structure
storage supports transaction processing. Test driver 110 or plugins
150 can read or write to compound files in transacted mode, where
changes made can subsequently be committed or reverted.
[0128] A. POLESS Components
[0129] FIG. 9 shows the major components that support POLESS and
the interfaces that connect the components. POLESS 300 may be
either exam resource file 120 or exam instance file 170. POLESS 300
utilizes PKware library component 330 for storage compression and
decompression. POLESS 300 uses Crypto API component 332, a
Microsoft application, for storage encryption and decryption.
Crypto API component 332 relies on a crypto service provided
("CSP") 334 to perform the actual encryption algorithms. Access to
the services of these components is facilitated by standard (API)
interfaces exposed by these components.
[0130] OLE2SS component 310 contains all the interface definition
that makeup structure storage. These interfaces can be realized by
any structured storage implementation, such as compound document
implementation OLE2 320 and POLESS 300. The interfaces include, for
example: IStream interface 340; ISequentialStream interface 342;
IStorage interface 344; and IRootstorage interface 346. POLESS 300
additionally implements IStreamVB interface 348 and IStorageVB
interface 350.
[0131] IStreamVB interface 348 supports several functions, for
example: ReadVB( ); WriteVB( ); Clear( ); Reset( ); get_sName( );
get_oStream( ); and CopyTo( ). ReadVB( ) reads a specified number
of bytes to a data array. WriteVB( ) writes the byte data to the
stream. Clear( ) clears the stream of all data. Reset( ) sets
position to the beginning of the stream. get_sName( ) is a
read-only function that returns the name of the stream.
get_oStream( ) is a read-only function that returns the IStream
interface 348. CopyTo( ) copies a source stream to a destination
stream.
[0132] IStorageVB interface 350 supports several functions, for
example: Clear( ); CommitVB( ); RevertVB( ); sElementName( );
bStorage( ); oElement( ); CreateStream( ); OpenStream( );
CreateStorage( ); OpenStorage( ); get_sName( ); get_oStorage( );
get_nCount( ); GetCompression( ); GetEncryption( ); GetCRC( );
CreateStreamLinked( ); CreatePropertyStg( ); OpenPropertyStg( );
SetClass( ); RegisterAlias( ); Destroy( ); and get_ElementType( ).
Clear( ) clears the storage of all elements. CommitVB( ) causes
transacted mode changes to be reflected in the parent. RevertVB( )
discards changes made since the last commit. sElementName( )
returns the name of the element. bStorage( ) returns TRUE if the
element is a sub-storage. oElement( ) returns IStreamVB interface
348 or IStorage interface VB 350 for the element. CreateStream( )
creates and opens a stream and returns IStreamVB interface 348.
[0133] OpenStream( ) opens a stream and returns IStreamVB interface
348. CreateStorage( ) creates and opens a nested storage and
returns IStreamVB interface 348. OpenStorage( ) opens an existing
storage and returns IStreamVB interface 348. get_sName( ) is a
read-only function that returns the name of the storage.
get_oStorage( ) is a read-only function that returns IStorage
interface 350. get_nCount( ) is a read-only function that returns a
count of the elements. GetCompression( ) returns the status of file
compression. GetEncryption( ) returns the status of file
encryption. GetCRC( ) returns the status of file CRC checking.
CreateStreamLinked( ) creates and opens a linked stream and returns
IStreamVB interface 348. CreatePropertyStg( ) creates and opens a
property storage and returns IPropertyStorageVB interface 414.
OpenPropertyStg( ) opens a property storage and returns
IPropertyStorageVB interface 414. SetClass( ) sets the CLSID for
the storage. RegisterAlias( ) registers a pluggable protocol.
Destroy( ) destroys the specified elements. get_ElementType( ) is a
read-only function that returns the type of the element.
[0134] B. POLESS Classes
[0135] FIGS. 10A and 10B illustrate the main class of POLESS 300,
the interfaces used to implement the classes, and the flow of the
creation of streams 424 and storages 426. cFileRoot class 400 is
the first object instantiated and is used to create a new or open
an existing a POLESS file. cStorageRoot class 406 is returned,
which is a slightly overloaded version of cStorage class 410. From
cStorageRoot class 406 creates or opens cStream class 408 and
cStorage class 410, from which any streams or storages and
sub-storages of those can be created or opened, respectively. For
instance, cStorage class 410 creates cPropertyStorage class 412,
which creates storage for property sets. The classes implement
interfaces that perform operations and/or define attributes that
further define the function or properties of the class. A complete
description of POLESS 300 classes and interfaces is included in
Appendix B.
[0136] 1) cFileRoot Class
[0137] cFileRoot class 400 is the root POLESS class and controls
the creation and opening of all POLESS files. cFileRoot class 400
is generally instantiated first before any other POLESS objects can
be created, although other sequences are possible. cFileRoot class
400 implements IFileRoot interface 401, which is collocated in FIG.
10 with cFileRoot class 400. IFileRoot interface 401 is used to
open one file at a time and is not released until all other storage
object 426, stream object 424, and property storage interfaces are
released and the file is ready to be closed. cFileRoot class 400
and IRoot interface support the following operations, for example:
StorageFileCreate( ); StorageFileOpen( ); CryptoGet( );
bStorageFile( ); StorageAmalgamatedGet( ); DeltaFileCreate( );
DeltaFileApply( ); GetObjectFromPath( ); CreateStreamFromBSTR( );
MemoryStreamFromStream( ); GetPicture( ); and SavePicture( ).
[0138] StorageFileCreate( ) creates a new storage file, returns the
root storage to interface, marks the new structured storage file as
a POLESS file by storing the class ID ("CLSID") of this class in a
stream in the root storage. StorageFileOpen( ) opens an existing
storage file and returns the root storage interface. CryptoGet( )
gets a default configured crypto class and should be set and used
on the open or create of the storage file. bStorageFile( ) returns
true if the file provided is an OLLE structured storage file and
not a POLESS storage file. StorageAmalgamatedGet( ) gets an empty
small cStorageAmalgamated class 404. DeltaFileCreate( ) creates a
POLESS difference file by comparing the original POLESS file to the
updated POLESS file. DeltaFileApply( ) applies a POLESS delta file
and applies the original POLESS file to the delta file to create an
updated POLESS file. GetObjectFromPath( ) uses monikers to retrieve
the object named by the path and returns a pointer to the object
retrieved. CreateStreamFromFile( ) creates a structured storage
stream and populates it with the contents of the file.
CreateStreamFromBSTR( ) creates a structures storage stream and
fills it with the specified string. MemoryStreamFromStream( ) is
used to copy a stream to a newly created memory stream object.
GetPicture( ) loads a picture from stream object 424. SavePicture(
) saves the picture into the stream 426.
[0139] 2) cCrypto Class
[0140] cCrypto class 402 controls the configuration of the
encryption/decryption of POLESS 300. cCrypto class 402 has the
following attributes, for example: sProviderName; eProviderType;
sContainerName; and sPassword. SProviderName represents the name of
CSP 334 being used to perform the encryption/decryption services.
eProviderType is the type of CSP 334. The field of cryptography is
large and growing. There are many different standard data formats
and protocols. These are generally organized into groups or
families, each of which has its own set of data formats and way of
doing things. Even if two families used the same algorithm, for
example, the RC2 block cipher, they would often use different
padding schemes, different key links, and different default modes.
Crypto API is designed so that a CSP provider type represents a
particular family. sContainerName is the key name and must be
provided by cCrypto class 402. sPassword is an optional password on
the public/private key pair and can only be entered by a human
operator. The password can be used for review disks and their
resource files.
[0141] cCrypto class 402 implements ICrypto interface 401 and they
support the following properties and method, for example:
ProviderName; Password; FileType; Algorithm; EnumProviders( ); and
EnumAlgorithms( ). Get_ProviderName( ) returns the name of the
Crypto provider. Put_ProviderName( ) sets the name of the Crypto
provider. Get_Password( ) and Put_Password( ) are only used for
sponsor resource files. Get_FileType( ) gets the file type and
put_FileType( ) sets the file type. Get_Algorithm( ) gets the
encryption algorithm and put Algorithm( ) sets the encryption
algorithm. EnumProviders( ) returns an enumerator for the list of
installed providers. EnumAlgorithms( ) enumerate a list of
algorithms for the current provider.
[0142] 3) cStorageAmalgamated Class
[0143] cStorageAmalgamated class 404 is an implementation of
IStorage interface 344. cStorageAmalgamated class 404 holds
references to an ordered collection of IStorage objects. When a
stream is opened, cStorageAmagalmated class 404 searches the
collection of storage objects in order to find the first storage
object that has the requested stream and returns this stream.
cStorageAmalgamated class 404 handles compound storage resolution
and delegates all other work to cStorage class 410.
cStorageAmalgamated class 404 is, for example, read-only.
cStorageAmalgamated class 404 will not allow stream or storages to
be created but is primarily for reading exam resource file 120.
cStorageAmalgamated class 404 implements IStorageAmalgamated
interface 405. cStorageAmalgamated class 404 and
IStorageAmalgamated interface 405 support the following operations,
for example: StorageAdd( ); ClearStorage( );
OpenStorageAmalgamated( ); and OpenPropertyStgAmalgamate- d( ).
StorageAdd( ) adds a new storage to the collection of storages.
ClearStorage( ) clears all the storage objects from the collection.
OpenStorageAmalgamated( ) opens a sub-storage of the current
amalgamated storages in an amalgamated fashion.
OpenPropertyStgAmalgamated( ) opens a property storage of the
current amalgamated storages in an amalgamated fashion.
Amalgamation is described in greater detail, in U.S. Patent
Publication No. 20030129573, entitled "EXTENSIBLE EXAM LANGUAGE
(XXL) PROTOCOL FOR COMPUTER BASED TESTING," incorporated herein by
reference.
[0144] 4) cStorageRoot Class
[0145] cStorageRoot class 406 is the POLESS implementation of
IStorage interface 344 and IRootstorage interface 346. cStorageRoot
class 406 handles any storage object 426 that is POLESS specific
and then delegates work to the cStorage class 410. IRootstorage
interface 346 supports the SwitchToFile( ) operation, which copies
the current file associated with the storage object to a new file,
which is then used for the storage object and any uncommitted
changes. cStorageRoot class 406 also implements IPersistFile
interface 418, which provides methods that permit an object to be
loaded from or saved to a disk file, rather than a storage object
or stream. Because the information needed to open a file varies
greatly from one application to another, the implementation of
IPersistFile::Load on the object preferably also open its disk
file. IPersistFile interface 418 inherits its definition from
IPersist, so all implementations must also include the GetClassID(
) method of IPersist interface 418.
[0146] 5) cStream Class
[0147] cStream class 408 is the POLESS implementation of IStream
interface 340. cStream class 408 handles any storage object 426
that is POLESS specific and then delegates work to compound
document implementation OLE2 320. The specific work includes
compression/decompression and encryption/decryption of stream
object 424.
[0148] IStream interface 340 supports the following operations, for
example: Seek( ); SetSize( ); CopyTo( ); Commit( ); Revert( );
LockRegion( ); UnlockRegion( ); Stat( ); and Clone( ). Seek( )
changes the seek pointer to a new location relative to the
beginning of stream object 424, the end of stream object 424, or
the current seek pointer. SetSize( ) changes the size of stream
object 424. CopyTo( ) Copies a specified number of bytes from the
current seek pointer in stream object 424 to the current seek
pointer in another stream object 424. Commit( ) ensures that any
changes made to a stream object 424 open in transacted mode are
reflected in the parent storage object. Revert( ) discards all
changes that have been made to a transacted stream since the last
call to IStream::Commit. LockRegion( ) restricts access to a
specified range of bytes in stream object 424. Supporting this
functionality is optional since some file systems do not provide
this operation. UnlockRegion( ) removes the access restriction on a
range of bytes previously restricted with IStream::LockRegion.
Stat( ) retrieves the STATSTG structure for the stream object 424.
Clone( ) creates a new stream object that references the same bytes
as the original stream but provides a separate seek pointer to
those bytes.
[0149] IStreamVB interface 348 is an automation friendly version of
IStream interface 340. IStreamVB interface 348 supports the
following operations, for example: Read( ); Write( ); Clear( );
Reset( ); get_sName( ); get_oStream; and CopyTo( ). Read( ) reads
data from stream object 424. Write( ) writes data, including the
entire byte array, to stream object 424. Clear( ) clears stream
object 424 of all data. Reset( ) resets the position in stream
object 424 to the beginning of stream object 424. Get_sName( )
returns the name of the stream. Get_Stream( ) returns the IDispatch
interface. CopyTo( ) copies the contents of a source stream to a
destination stream.
[0150] 6) cStorage Class
[0151] cStorage class 410 is the POLESS implementation of IStorage
interface 344 and IcStorage interface 411. cStorage class 410
handles any storage object 426 that is POLESS specific and then
delegates work to compound document implementation OLE2 320.
[0152] IStorage interface 344 supports the following operations,
for example: CreateStream( ); OpenStream( ); CreateStorage( );
OpenStorage( ); CopyTo( ); MoveElementTo( ); Commit( ); Revert( );
EnumElements( ); DestroyElement( ); RenameElement( );
SetElementTimes( ); SetClass( ); SetStateBits( ); and Stat( ).
CreateStream( ) creates and opens a stream object 424 with the
specified name contained in a storage object. OpenStream( ) opens
an existing stream object 424 within a storage object using
specified access permissions. CreateStorage( ) creates and opens a
new stream object 424 within a storage object. OpenStorage( ) opens
an existing storage object 426 with the specified name according to
the specified access mode. CopyTo( ) copies the entire contents of
an open storage object 426 into another storage object. The layout
of the destination storage object may differ from the layout of the
source storage object. MoveElementTo( ) copies or moves a
sub-storage or stream object 424 from one storage object 426 to
another storage object.
[0153] Commit( ) reflects changes for a transacted storage object
426 to the parent level. Revert( ) discards all changes that have
been made to the storage object 426 since the last IStorage::Commit
operation. EnumElements( ) returns an enumerator object that can be
used to enumerate storage objects 426 and stream objects 424
contained within a storage object. DestroyElement( ) removes the
specified storage object 426 or stream object 424 from a storage
object. RenameElement( ) renames the specified storage object 426
or stream object 424 in a storage object. SetElementTimes( ) sets
the modification, access, and creation times of the indicated
storage element, if supported by the underlying file system.
SetClass( ) assigns the specified CLSID to a storage object.
SetStateBits( ) stores state information in a storage object, for
example up to 32 bits. Stat( ) returns the STATSTG structure for an
open storage object.
[0154] IStorageVB interface 350 is an automation friendly version
of IStorage interface 344. IStorageVB interface 350 supports the
following operations, for example: Clear( ); Commit( ); Revert( );
sElementName( ); bStorage( ); bElement( ); CreateStream( );
OpenStream( ); Createstorage( ); OpenStorage( ); get_sName( );
getoStorage( ); get_nCount( ); GetCompression( ); GetEncryption( );
GetCRC( ); CreateStreamLinked( ); CreatePropertyStg( );
OpenPropertyStg( ); SetClass( ); RegisterAlias( ); Destroy( ); and
get_ElementType( ). Clear( ) clears the storage of all elements,
e.g. sub-storages and streams. Commit( ) ensures that any changes
made to a storage object opened in transacted mode are reflected in
the parent storage. For non-root storage objects in direct mode,
this method has no effect. For a root storage, it reflects the
changes in the actual device, for example, a file on disk. For a
root storage object open in direct mode, the commit( ) method is
always called prior to releasing the object. Commit( ) flushes all
memory buffers to the disk for a root storage in direct mode and
will return an error code upon failure. Although releasing the
object also flushes memory buffers to disk, it has no capacity to
return any error codes upon failure. Therefore, calling releasing
without first calling commit( ) causes indeterminate results.
Revert( ) discards all changes that have been made to the storage
object since the last Commit( ) operation.
[0155] sElement( ) returns the name of the element. bStorage( )
returns true if the element is a sub-storage. bElement( ) returns
either iStreamVB interface 412 or iStreamVB interface 414 or
IStorageVB interface 412 for the selected element. CreateStream( )
creates and opens a stream object with the specified name contained
in the storage object. Nothing is returned if the stream cannot be
created. OpenStream( ) opens an existing stream object within this
storage object in the specified access mode. Nothing is returned if
the stream cannot be opened. CreateStorage( ) creates and opens a
new storage object nested within the storage object. Nothing is
returned if the storage cannot be created. OpenStorage( ) opens an
existing storage object with a specified name in the specified
access mode. Nothing is returned if the storage cannot be opened.
Get_sName( ) returns the name of the storage. Get_oStorage( )
returns the IDispatch interface, which exposes objects, methods and
properties to programming tools and other applications that support
Automation. COM components implement the IDispatch interface to
enable access by Automation clients, such as Visual Basic.
[0156] Get_nCount( ) returns the count of elements in the storage.
GetCompression( ) determines if streams may be compressed in the
file and if enabled streams may optionally be compressed when
created. GetCRC( ) indicates whether a cyclic-redundancy-check
("CRC"), or a digital signature, check is to be performed on the
file. CreateStreamLinked( ) creates a link to a stream in another
POLESS file. CreatePropertyStg( ) creates a property storage.
OpenPropertyStg( ) opens a property storage. SetClass( ) assigns
the specified CLSID to a storage object. RegisterAlias( ) registers
an alias to a storage in the POLESS file for access by the
pluggable protocol. Destroy( ) destroys the specified element.
Get_ElementType( ) is a read-only command that returns the type of
the element.
[0157] 7) cPropertyStorage Class
[0158] cPropertyStorage class 412 implements IPropertyStorage
interface 413, which supports the following operations, for
example: ReadMultiple( ); WriteMultiple( ); DeleteMultiple( );
ReadPropertyNames ( ); WritePropertyNames( ); DeletePropertyNames(
); SetClass( ); Commit( ); Revert( ); Enum( ); Stat( ); and
SetTimes( ). ReadMultiple( ) reads property values in a property
set. WriteMultiple( ) writes property values in a property set.
DeleteMultiple( ) deletes property values in a property set.
ReadPropertyNames( ) gets corresponding strung names fro given
property identifiers. WritePropertyNames( ) creates or changes
string names corresponding to given property identifiers.
DeletePropertyNames( ) deletes string names for given property
identifiers. SetClass( ) assigns a CLSID to a property set. Commit(
) flushes or commits changes to a property storage object, as is
done with the command IStorage::Commit, described previously.
Revert( ) discards all changes made since the last commit call when
a property storage is opened in transacted mode. Enum( ) creates
and gets a pointer to an enumerator for properties within a
property set. Stat( ) receives statistics about a property set.
SetTimes( ) sets modification, creation, and access times for a
property set.
[0159] IPropertyStorageVB interface 414 is an automation friendly
version of IPropertyStorage interface 413 that manages the
persistent properties of a single property set. IPropertyStorageVB
interface 414 supports the following operations, for example:
ReadVB( ); WriteVB( ); Delete( ); CommitVB( ); RevertVB( );
SetClass( ); get_nCount( ); CopyTo( ); GetName( ); WriteMultiple(
); and ReadMultiple( ). ReadVB( ) reads the value of a specified
property from the property set. WriteVB( ) writes a value for a
specified property to the property set. If the property does not
exist the property/value pair will be created. If the property
already exists, the value will be updated if opened in
eAccess_Write mode. Delete( ) removes a property from the property
set. CommitVB( ) flushes or commits changes to a property storage
object, as is done with the command IStorage::Commit, described
previously. RevertVB( ) discards all changes made since the last
commit call when a property storage is opened in transacted mode.
SetClass( ) assigns the specified CLSID to a property storage
object. Get_nCount( ) returns the count of properties in the
property set. CopyTo( ) copies the contents of the source property
set to a destination property set. GetName( ) returns the name of
the specified property. WriteMultiple( ) writes property values in
a property set. ReadMultiple( ) reads property values in a property
set.
[0160] 8) cPropertyStorageAmalgamated Class
[0161] cPropertyStorageAmalgamated class 416 implements
IPropertyStorageAmalgamated interface 417, which supports the
following operations, for example: PropertyStorageAdd( ) and
ClearStorage ( ). PropertyStorageAdd ( ) adds a property set to the
collection of property sets. ClearStorage( ) clears the collection
of property sets.
[0162] C. POLESS Exam Resource File
[0163] FIGS. 11 and 12-25 illustrate the POLESS layout of exam
resource file 120. Exam resource file 120 stores the various pieces
of compiled information from exam source files 130, as shown in
FIG. 5. Exam resource file 120 contains all of the content required
to deliver the test. However, where the test is media-intense, exam
resource file 120 will contain the core elements for the test with
"links" to the external content. XXL compiler 140 and plugins 150
store the compiled information to exam instance file 120 using one
of IPersistResourceStream interface 192a, IPersistResourceSet
interface 192b, or IPersistResourceStore interface 192 to store the
compiled information as a stream of data, a set of data, or a
storage element, respectively. In a preferred embodiment, the
layout of exam resource file 120 is in a hierarchical POLESS format
that directly implements the format of the XXL test definition
language. The test developer uses the XXL test definition language
to create the logic files 230 and data files 212 (FIG. 5) of exam
source file 130. By having a storage structure that follows the
format of the XXL test definition language, the incremental access
aspect of POLESS is easily implemented. XXL compiler 140 determines
the storage location in exam resource file 120 that stores a
particular piece of compiled information, even information stored
into exam resource file 120 by one of plugins 150.
[0164] FIG. 11 illustrates the main storage branches of exam
resource file 120, which corresponds to the top-level elements of
the XXL test definition language, denoted by reference numeral 500.
The main storage branches of exam resource file 120 are, for
example: exams branch 550; forms branch 600; items branch 650;
category branch 700; templates branch 750; sections branch 800;
groups branch 850; plugins branch 900; data branch 950; formGroups
branch 1000; attributes branch 1050; scripts branch 1100; and
message box ("Msgbox") branch 1150. Other storage branches may
alternatively be used.
[0165] Exam branch 550, as seen in FIG. 12, stores, for example,
the primary attributes, properties, and data that govern the test.
Exam branch 550 can store information for various tests, as is
denoted by the three, vertical ellipses. A specific test is
identified by the data stored in name attribute storage 552. Again,
the various tests may each be identified by a different name, as
denoted by the solid border around name attribute storage 552 or
other identification scheme. Attributes storage 554 stores, for
example, version information 555, and title information 556 of the
test as a stream of data or other data storage format. Title
information 556 is optional, as is denoted by the broken border.
Any optional, customized information regarding the test is stored
in custom properties 558 as a property storage or other data
storage format. Information relating to the forms of the test are
optionally stored in forms property storage 560. A form is a fixed
or substantially fixed order of testing events. Many different
forms can be stored in forms storage 560, giving flexibility to
test driver 110 in controlling progression of the test. FormGroups
storage 562 optionally stores information relating to a collection
of exam forms as a stream of data or other data storage format.
Preferably, a single form from the formGroup is chosen to deliver
to an examinee. The selection of the form from the group is
performed by a selection plugin 160. Exam branch 550 preferably
contains at least one forms storage 560 either independently or
within formGroups storage 562. Other information relating to the
test may be stored under exam branch 550. Other storage formats may
optionally be used
[0166] Forms branch 600, as seen in FIGS. 13A and 13B, stores, for
example, the primary attributes, properties, and data that govern
the progress of the test. Forms branch 600 can store information
for various forms, as is denoted by the three, vertical ellipses.
As described previously, a form is a fixed or substantially fixed
or substantially fixed order of testing events. A single form is
identified by the data stored in name attribute storage 602. Other
identification formats may optionally be used. Again, the various
forms may each be identified, for example, by a different name, as
denoted by the solid border around name attribute storage 602.
Attribute storage 604 stores, for example, begin section
information 605, end section information 606, event information
607, and optionally stores version information 608, title
information 609, skip allowed information 610, restartable
information 611, with information 612, height information 613, and
bit depth information 614. All information stored in attribute
storage 604 is stored as a stream of data or other data storage
format. Begin section information 605 and end section information
606 indicates, for example, respectively, which section of the test
begins and ends the test.
[0167] Event information 607 indicates, for example, the order of
events of the test for that form. Each event has a name and is
prefixed with an event type and a colon. Other formats are
optional. The event type includes "section", "report", and
"results". Version information 608 and title information 609
indicate the version and title of the form, respectively. Skip
allowed information 610 indicates, for example, whether or not by
default skipping of sections is allowed. Restartable information
611 indicates, for example, whether the form can be restarted. Any
optional, customized information regarding the form is stored in
custom storage 616 as a property set or other data storage format.
Timer storage 628 stores, for example, information relating to how
the form is to be timed as a storage element. Attributes storage
630 stores, for example, the names of Timer Plugin 158 to be used
with the form. Plugin data storage 632 and plugin data storage 633
store any data necessary for timer plugin 158 as a storage element
and a stream of data, respectively. Plugin data storage 632 and
plug in data storage 633 are optional. Scoring storage 634 stores,
for example, information relating to the scoring of the form.
Attributes storage 636 stores, for example, the name of scoring
plugin 164 to be used with the form. Plugin data 638 and plugin
data 639 optionally store any data needed for scoring Plugin 164 as
a storage element and a stream of data respectively.
[0168] Items Branch 650, as seen in FIG. 14, stores, for example,
the primary attributes, properties, and data that govern the items,
or test questions, to be delivered to the examinee during the test.
Items branch 650 can store information for various items, as is
denoted by the three, vertical ellipses. A single item is
identified by the data stored in name attributes storage 652.
Again, the various items may each be identified by a different
name, as denoted by the solid border around name attributes storage
652. Attributes storage 654 stores, for example, weight information
654, scored information 655, and optionally stores skip allowed
information 656, title information 657, start information 658,
finish information 659, and condition information 660. Weight
information 654 indicates, for example, a value used for judging
and scoring the item. In one embodiment, by default an item is
given a weight of one in accordance with one embodiment, but other
values may be utilized. Scored information 655 indicates, for
example, whether or not the item is scored as opposed to whether
the item is being used as an example. The default of scored
information 655 is true. Skip allowed information 656 indicates,
for example, whether the examinee can skip the item without
answering.
[0169] Start information 658 indicates, for example, script
execution at the beginning of the item and finish information 659
indicates, for example, script execution at the end of the item.
Condition information 660 indicates, for example, whether or not
there is a condition on the item being delivered to the examinee.
The information stored in attributes storage 654 is stored as a
stream of data or other data storage format. Data storage 662 and
data stream 664 store any information regarding the properties of
the item. For example, data storage 662 or data stream 664 can
store the correct answer of a multiple choice item. Data storage
662 and data stream 664 stored the information as a storage element
and a stream of data respectively.
[0170] Any optional, customized information regarding the item is
stored in customs storage 666 as a stream of data or other data
storage format. Category storage 668 stores, for example,
information relating to each category to which the item belongs.
The information stored in category storage 668 preferably and
optionally is redundant, as category branch 700 stores, for
example, all the items within the specific categories. The reason
for the optional redundancy is so that test driver 110 can quickly
look up the category of any item.
[0171] Category branch 700, as seen in FIG. 15, stores, for
example, the primary attributes, properties, and data that govern
the test categories. A test category provides a grouping mechanism,
which is independent of delivery of the test, allowing for exotic
reporting and scoring if necessary. Category branch 700 is optional
as denoted by the broken border. Category branch 700 can store
information for various categories, as is denoted by the three,
vertical ellipses. A single category is identified by the data
stored in name attributes storage 702. Again, the various
categories may each be identified by a different name, as denoted
by the solid border around name attributes storage 702. Attributes
storage 704 stores, for example, complete information 705,
duplicates information 706, contents information 707, and
optionally stores, for example, description information 708.
Complete information 705 indicates, for example, whether or not
every item in the category must appear within the category or
within its subcategories. Duplicates information 706 indicates, for
example, whether the item can appear more than once within the
category or within the subcategories. Contents information 707
determines what can exist within a category.
[0172] Description information 708 is used within the category to
contain a description of the category's contents. Category storage
710 stores, for example, information relating to any subcategories
under the category identified in name attribute storage 702. Items
storage 712 indicates, for example, any items that exist within the
category. Sections storage 714 contains information indicating what
any sections that exist within the category. Scoring storage 716
contains information relating to the scoring of the items within
the category. Attributes storage 718 stores, for example, the name
of the scoring plugin to be used with the item. Data storage 720
and data stream 722 contain the information needed to initialize
scoring plugin 164. Data storage 720 and data stream 722 store the
information as a storage element and a stream of data
respectively.
[0173] Templates branch 750, as seen in FIG. 16, stores, for
example, the primary attributes, properties, and data that govern
the templates used in the test. Template branch 750 can store
information for various main templates, as is denoted by the three,
vertical ellipses. A single main template is identified by the data
stored in name attributes storage 752. Again, the various templates
may each be identified by a different name, as denoted by the solid
border around name attributes storage 752. Attributes storage 754
stores, for example, split information 756, order information 757,
and optionally stores size information 759. Split information 656
defines how a specific area within the template is to be split or
separated, for example, either by rows or columns or other shapes
and/or sizes. Size information 759 indicates, for example, possible
values for describing the size of the template, for example,
pixels, percentages, or html syntax. Template storage 760 stores,
for example, information relating to any sub-templates to be used
under the templates specified by the information in name attributes
storage 752. Sub-templates are identified by the information in
name attributes storage 762. Many sub-templates 760 can exist as
denoted by the three vertical ellipses.
[0174] Areas storage 764 indicates, for example, information
relating to the areas used within the template denoted by the
information in name attributes storage 752. Many areas may exist
within a template as denoted by the three vertical ellipses. Each
area is identified by the information stored in name attribute
storage 766. Attribute storage 768 stores, for example, visible
plugin name information 760, size information 770, and allow more
information 771. Plugin name information 760 indicates, for
example, the name of the visible plugin to be used with the area.
Size information 770 indicates, for example, the size of the area,
as for example a pixel value, a percentage value, or HTML syntax.
Plugin data 772 and plugin data 774 store information relating to
the visible plugin to be used in the area. The data stored in
either plugin data storage 772 or plugin data stream 774 is
executed by the visible plugin when the template is loaded. Plugin
data storage 772 and plugin data stream 774 stores, for example,
the information as either a storage element or a stream of data,
respectively. Other information may optionally be stored.
[0175] Section branch 800, as seen in FIG. 17, stores, for example,
the primary attributes, properties, and data that govern test
sections. Test sections dictate the navigation and timing of groups
of items as well as displays within the test. Sections branch 800
can store information for various sections, as is denoted by the
three, vertical ellipses. A single section is identified by the
data stored in name attribute storage 802. Again, the various
sections may each be identified by a different name, as noted by
the solid border around name attributes storage 802. Attributes
storage 804 stores, for example, group information 805 and
optionally stores title information 806, skip allowed information
807, start information 808, finish information 809, and condition
information 810. Group information 805 indicates, for example, to
which group of the test the section belongs. Skip allowed
information 807 indicates, for example, whether or not the items
within the section may be skipped. Start information 808 indicates,
for example, script execution at the beginning of the section and
finish information 809 indicates, for example, script execution at
the end of the section. Condition information 810 indicates, for
example, any conditions that exist regarding the section. Any
optional, customized information regarding this section is stored
in custom property storage 812 as a stream of data or other data
storage format. Custom attributes will be stored as a property set.
The "key" for each attribute will be a string or other acceptable
format.
[0176] Timer storage 814 stores information regarding, for example,
the timing of the section. Attribute storage 816 stores, for
example, information identifying timer plugin 158, which is to be
used with a section. Plugin data storage 818 and plugin data
storage 820 stores, for example, data needed for timer plugin 158.
Plugin data storage 818 and plugin data storage 820 stores, for
example, information as a storage element and a string of data, or
other acceptable format, respectively. Navigation storage 822
stores, for example, information relating to the delivery of
presentations and groups within the section. Attributes storage 824
stores, for example, information indicating which navigation plugin
162 is to be used with this section. Plugin data storage 826 and
plugin data stream 828 store information needed for the navigation
plugin 162. Plugin data storage 826 and plugin data stream 828
store the information as a storage element and a stream of data
respectively. Groups branch 850, as seen in FIG. 18, stores, for
example, the primary attributes, properties, and data that govern
the groups within the test. A group determines the order of events
within the test. Groups branch 850 can store information for
various groups, as is denoted by the three, vertical ellipses. A
single group is identified by the data store in name attributes
storage 852. The various groups may each be identified by a
different name, as noted by the solid border around name attributes
storage 852. Attributes storage 854 stores, for example, type
information 855, event information 856, title information 857, and
reviewed name information 858. Type information 855 indicates, for
example, whether the group is either a "group holder" (group of
presentations), or a "section holder" (group of sub-sections).
These are mutually exclusive.
[0177] Event information 856 indicates, for example, the order of
events within the test. Review name information 858 indicates, for
example, whether or not a presentation within the group is to be
used as a review screen. Any optional, customized information
regarding the group is stored in custom storage 860 as a stream of
data or other data storage format. Events storage 862 stores event
information, for example, as is described in further detail in FIG.
19. Scoring storage 864 stores, for example, information relating
to the scoring of items within the group. Attributes storage 866
stores, for example, information indicating which scoring plugin
164 is to be used with the group. Selection storage 872 stores, for
example, information relating to the selection of items within the
group. Attributes storage 874 indicates, for example, which
selection plugin 160 is to be used with the group.
[0178] FIGS. 19A, 19B, 19C, and 19D illustrate the events
sub-branch of groups branch 850 in greater detail, in accordance
with one embodiment of the invention. In FIG. 19A, events
sub-branch 862 can store information for various events. For
example, events sub-branch 862 is storing information in events
name sub-branch 880, event name sub-branch 890, and event name
sub-branch 897. Attributes storage 881, in FIG. 19B, under events
name storage 880 stores, for example, type information 882,
template information 883, and optionally stores title information
884, counted information 885, start information 886, finish
information 887, and condition information 888. Type information
882 indicates, for example, whether the event is an item or a
display. Template information 883 indicates, for example, which
template is being used with the event. Counted information 885
indicates, for example, whether a presentation should be included
in the totals of presentations presented to the examinee in a
section. Generally, presentations with items, or questions, are
counted and introductory presentations are not counted.
[0179] Start information 886, finish information 887, and condition
information 888 indicates, for example, start, finish, and
conditional scripts respectively. Any optional, customized
information regarding the event is stored in custom storage 889.
The "key" for each custom attribute will be a string. Referring
again to FIG. 19A, event name storage 890 indicates, for example, a
different event, which contains different attributes. Additionally,
area information 891, in FIG. 19B, indicates, for example, which
area is rendering the presentations content and item information
892 indicates, for example, the name of the associated item if the
event is of the item type. Additionally, data storage 893, data
stream 894, data storage 895, and data storage 896 contain
information used in a nested presentation. The data off of a nested
presentation are the contents of the item or the presentation. This
data may be a stream, a storage, a link to a stream, a link to a
storage, or other format. In FIG. 19C, event name 897 indicates,
for example, another event, which includes a sub-event 898, in FIG.
19D.
[0180] Plugins branch 900, as seen in FIG. 20, stores, for example,
the primary attributes, properties, and data that govern any
plugins 150 used for the test. Plugins branch 900 can store
information for various plugins, as is denoted by the three,
vertical ellipses. A single plugin is identified by the data stored
in name attribute storage 902. A CLSID is stamped with the name of
the plugin 150. Attributes storage 904 stores, for example,
information identifying the plugin 150 by a program ID. Data
storage 906 and data storage 908 store initial data for the plugin
as either a storage element or a stream of data respectively.
[0181] Data branch 950, as indicated in FIG. 21, stores, for
example, any global data needed for the test. Data stored
optionally under data branch 950 may be stored as either a storage
element or a stream of data as indicated by data storage 952 and
data storage 954. Data stored under data branch 950 may be directly
used by a plugin 150 or the data may be resources (.gif, .jpeg,
.wab, .mpeg, etc.) used internally by a plugin 150.
[0182] FormGroups branch 1000, as seen in FIG. 22, stores, for
example, the primary attributes properties and data that govern the
formGroups of the test. FormGroups branch 1000 can store
information for various formGroups, as is denoted by the three,
vertical ellipses. A single formGroup is identified by the data
stored in name attributes storage 1002. The various formGroups may
each be identified by a different name, as denoted by the solid
border around name attributes storage 1002. Attributes storage 1004
stores, for example, information indicating which forms are to be
used within the formGroup. Selections storage 1006 stores, for
example, information relating to the selection of items within the
formGroup. Attributes storage 1008 indicates, for example, which
selection plugin 160 is to be used with the formGroup. Plugin data
storage 1010 and plugin data storage 1012 store any information
needed for the selection plugin 160. Attributes storage branch 1050
stores, for example, attribute information that is global to exam
resource file 120. This includes the last execution state of XXL
compiler 140 [sMode], the major [iXXLMajorVersion] and the minor
version [iXXLMinorVersion] of the XXL language.
[0183] Scripts branch 1100 stores, for example, information
relating to scripts used within the test. Attributes storage 1102
stores, for example, type information that specifies which type of
language the script is in, for example, VB script of J script.
Scripts storage 1104 stores, for example, global scripts used
within the test that may be referenced by the test driver. MsgBox
branch 1150 stores, for example, information relating to the size
and content of any message boxes that may be delivered to the
examinee during the test. Message boxes may be triggered by plugins
150 during the exam.
[0184] D. POLESS Exam Instance File
[0185] FIGS. 26A, 26B, 26C, and 26D illustrate the POLESS layout of
exam instance file 170. Exam instance file 170 stores information
regarding the current examinee's test. Exam instance file 170 is
created when a test starts for an examinee. Exam instance file 170
is destroyed when the test successfully completes. If the examinee
must restart her test due to some interruption, for example, a
power failure, the state of the test is restored from Exam instance
file 170. In a preferred embodiment, the layout of exam instance
file 170 is in a hierarchical POLESS format. As seen in FIG. 26A,
the top-level storage branches of exam instance file 170 from root
1200 are, for example: running branch 1202; contents branch 1310;
and history branch 1320. Root 1200 relates to POLESS cStorageRoot
class 406 (FIG. 10), which instantiates exam instance file 170.
[0186] Running branch 1202 stores, for example, the state
information of all running objects in test driver 110 and plugins
150. Plugins 150 use one of IPersistInstanceStream interface 196a,
IPersistInstanceSet interface 196b, or IPersistInstanceStore
interface 196c to store information to exam instance file 170 as a
stream of data, a set of data, or a store of data, respectively.
Any of plugins 150, except display plugin 152, results plugin 166,
report plugin 168, and helm plugin 154, which do not contain
examination state information, store examination state information
to exam instance file 170. Test driver 110 determines the storage
location in exam instance file 170 that stores a particular piece
of examination state information.
[0187] Exam sub-branch 1204 contains examination state information
relating to the exam. Contents storage 1206 stores, for example,
exam status information 1207 and version information 1208. Exam
status information 1207 indicates, for example, the status of the
exam, for example, initializing or terminating. Template storage
branch 1210 stores, for example, examination state information
relating to templates running in the exam. Name attribute storage
1212 stores, for example, count information 1214 and observed ever
information 1215. Observed ever information 1215 indicates, for
example, whether or not the template's content has ever been fully
seen by the examinee.
[0188] Form storage branch 1216 contains information relating to
the forms used within the exam. Contents storage branch 1218
stores, for example, seconds information 1219, date start
information 1220, date finish information 1221, current section
information 1222, and version information 1223. Current section
information 1222 indicates, for example, the current section being
delivered to the examinee in the form. Version information 1223
indicates, for example, the identification of the form.
[0189] Sections chosen storage branch 1224, as illustrated in FIG.
26B, stores, for example, information relating to sections in the
form being delivered to the examinee. Contents storage 1226 stores,
for example, the names of the sections that have been or will be
delivered to the examinee. Name attribute storage 1228 indicates,
for example, the name of a particular section. Contents storage
1230 stores, for example, current child information 1231, seconds
information 1232, date start information 1233, and date finish
information 1234. Navigation storage 1236 and navigation storage
1237 store the state information of navigation plugin 162.
Navigation storage 1236 stores, for example, the examination state
information from navigation plugin 162 if navigation plugin 162
implements the IPersistInterfaceSet 196b or IPersistInterfaceStore
196c. Navigation storage 1237 stores, for example, the information
from navigation plugin 162 if navigation plugin 162 implements
IPersistInterfaceStream 196a. Timers storage 1238 and timers
storage 1239 store information from timer plugin 158. Timer storage
1238 is used if timer plugin 158 implements IPersistInterfaceSet
196b or IPersistInterfaceStore 196c. Timers storage 1239 is used if
timer plugin 158 uses IPersistInterfaceStream 196a.
[0190] Items chosen sub-branch storage 1240 stores, for example,
information relating to items that have been or will be delivered
to the examinee. Contents storage branch 1242 stores, for example,
the names and order of all the items that have been or will be
delivered to the examinee. Name attributes storage 1244 indicates,
for example, the identification of a particular item. Contents
storage branch 1246 stores, for example, presented information
1244, complete information 1248, skipped information 1249, seconds
information 1250, dehydrated information 1251, and observed ever
information 1252. Presented information 1247 indicates, for
example, whether the item has ever been delivered to the examinee.
Completed information 1248 indicates, for example, whether or not
the item has been completed. Skipped information 1249 indicates,
for example, whether the item has been skipped. Item plugin storage
1254 and item plugin storage 1255 stores, for example, examination
state information from item plugin 156. Item plugin storage 1254 is
used if item plugin 156 uses IPersistInterfaceSet 196b or
IPersistInterfaceStore 196c. Item plugin storage 1255 is used if
item plugin 156 uses IPersistInterfaceStream 196a.
[0191] In FIG. 26C, item light storage 1256 exists only if the item
was dehydrated (to save memory or when a section ends). The
dehydrated item stores the data but actions on the data are no
longer available until the item is re-hydrated. Item light storage
1256 stores, for example, score candidate information 1257. Score
minimum information 1258, score nominal information 1259, score
maximum information 1260, complete information 1261, skipped
information 1262, correct answer display 1263, response results
1264, and correct answer results 1266. Timers storage 1268 and
timers storage 1269 store information from timer plugin 158. Timer
storage 1268, as seen in FIG. 26B, is used if timer plugin 158
implements IPersistInterfaceSet 196b or IPersistInterfaceStore
196c. Timers storage 1269 is used if timer plugin 158 uses
IPersistInterfaceStream 196a. Score storage 1270 and Score storage
1271 store information from timer plugin 158. Timer storage 1270 is
used if timer plugin 158 implements IPersistInterfaceSet 196b or
IPersistInterfaceStore 196c. Score storage 1271 is used if timer
plugin 158 uses IPersistInterfaceStream 196a.
[0192] In FIG. 26C, groups chosen sub-branch storage 1272
indicates, for example, which groups have been or will be delivered
to the examinee. Contents storage 1274 stores, for example, the
names of the groups. Name attributes storage 1276 indicates, for
example, the name of a particular group. Contents storage 1278
stores, for example, names of groups and the order of groups.
Scoring storage 1280 and scoring storage 1281 store examination
state information from score plugin 164. Scoring storage 1280 is
used if score plugin 164 implements IPersistInterfaceSet 196b or
IPersistInterfaceStore 196c. Scoring storage information 1281 is
used if score plugin 164 implements IPersistInterfaceStream 196a.
Selection storage 1282 and selection storage 1283 store information
from selection plugin 160. Selection storage 1282 is used if
selection plugin 160 implements IPersistInterfaceSet 196b or
IPersistInterfaceStore 196c. Selection storage 1283 is used if
selection plugin 160 implements IPersistInterfaceStream 196a.
Delivered storage 1284, in FIG. 26D, stores, for example, an
ordered list of groups chosen for delivery. Delivered storage 1285
stores, for example, an ordered list of the sub-classes of the
form, for example: sections, reports and results.
[0193] Presentations chosen storage sub-branch 1286 indicates, for
example, any presentations that have been or will be delivered to
the examinee. Contents storage 1288 stores, for example, the names
of the presentations. Names storage sub-branch 1290 stores, for
example, the name of the presentation. Names storage 1290 also
stores, for example, comment information 1291, marked information
1292, count information 1293, name information 1294, observed ever
information 1295, name information 1296, and observed ever
information 1297. Name information 1294 and observed information
1295 relate to the name of the first presentation area stored under
presentations chosen sub-branch 1286 and whether or not the
presentation has ever been observed, and name information 1296
indicates, for example, the last presentation area that was
delivered to the examinee and whether or not the presentation was
ever observed. Contents storage 1298 stores, for example,
information leading to events. Contents storage 1298 stores, for
example, ready information 1299 ever checked information 1300, ever
started information 1301, and ever finished information 1302. Ready
information 1299 indicates, for example, whether the event is ready
to be delivered to the examinee. Ever checked information 1300
indicates, for example, whether an event's conditional delivery
script ever been checked. Preferably, the conditional delivery
script is only checked once. Ever started information 1301
indicates, for example, whether the event was ever started by the
examinee. Ever finished information 1302 indicates, for example,
whether the event was completed by the examinee.
[0194] Referring again to FIG. 26A, contents branch 1310 stores,
for example, a property set containing information to identify the
examination instance and the examination start count 1312. The
identifying information used is the examinee appointment
identification 1311, the name 1313 of exam resource file 120, and
the name 1314 of the specified form or group.
[0195] History branch 1320 is a single stream of chronological text
messages that logs the history of the test. These text messages are
used by staff at system headquarters to diagnose problems that
occurred in the field. Each text message is prefixed with the date,
time, and a level of severity, for example: information, warning,
or error. Test driver 110 will filter the text messages to a level
of diagnostics desired for test driver 110, such as determining
errors in test driver 110 or detail history tracking, including
general information.
[0196] V. Expansion of Test Driver Using Plugins
[0197] FIG. 27 illustrates the process for customizing test based
on specific requirement from the client using plugins 150, denoted
generally by reference numeral 1400. First, the client presents the
new requirements, for example, a new item type, to the test
developer, step 1402. The test developer then writes and XML schema
to define the XXL test specification, step 1404. The schema is
subsequently used to validate the XXL test specification.
[0198] A detailed description of the XXL schema is given in U.S.
Patent Publication No. 20030129573, entitled "EXTENSIBLE EXAM
LANGUAGE (XXL) PROTOCOL FOR COMPUTER BASED TESTING," incorporated
herein by reference.
[0199] The test developer next writes the appropriate plugin 150,
in this example, item plugin 156. The test developer also
implements the IPlugin interface 167 and IPlugin interface and
IItem interfaces 169. Additionally, the test developer implements
IPersistResource interface 192 (FIG. 3) to enable persistence of
compiled test information from item plugin 156 to exam resource
file 120. The test developer can optionally implement
IPersistInstance interface 196 (FIG. 3), step 1408, to enable
persistence of examination state information from item plugin 156
to exam instance file 170. After the appropriate interfaces have
been implemented, item plugin 156 is valid and operating. Finally,
after the test is delivered to the examinee, the result processor
accumulates results from the examinee, 1410. The results processor
must be able to understand the new item type to correctly process
the results. Customization process 1400 only required the test
developer to write one piece of software, item plugin 156, to
accommodate the client's customizations rather than multiple pieces
of software.
[0200] A. Test Production and Test Delivery
[0201] FIG. 28 is a flow chart illustrating the overall method of
test production and test delivery, denoted generally by reference
numeral 1500. The test publisher first authors the test
specification and content, step 1502. The test specification and
content are then stored in exam source files 130, step 1504. Exam
source files 130, for example the content of XXL files 134, are
then compiled and validated, step 1506. The compiled test
specification and content are stored in exam resource file 120,
step 1508. Finally, the compiled test specification and content are
delivered to the examinee, step 1510.
[0202] The validation of the test specification and content is
illustrated in greater detail in FIG. 29, by the method denoted
generally by reference numeral 1512. When the test specification
and content stored in exam source files 130 specifically references
a plugin 150, that plugin 150 is instantiated, step 1514. Partial
test specification and content relating to that plugin 150 are
loaded into the plugin 150 from exam source files 130, step 1516.
In an alternative embodiment, the partial test specification and
content are loaded into a private memory in data communication with
the plugin 150. The plugin 150 validates the partial test
specification and content, step 1518. The validated test
specification and content are then unloaded from the plugin 150
into a storage element within exam resource file 120.
[0203] FIG. 30 illustrates the method of the test delivery cycle in
greater detail. When the previously validated test specification
and content stored in exam resource file 120 references a plugin
150, the plugin 150 is instantiated, step 1525. The storage element
in exam resource file 120 containing the validated test
specification and content are provided to the plugin 150, step
1527. The validated test specification and content are loaded into
the plugin 150 from the storage element within exam resource file
120, step 1529. Finally, the examination state information, which
includes, for example, the examinee's responses, is stored into
exam instance file 170, step 1533.
[0204] FIG. 31 illustrates the method of restarting a test after
interruption in greater detail. In test restart method 1535, test
driver 110 is started, step 1537. Test driver 110 determines
whether the test has already started, step 1539. If the test
delivery has not already started, plugins 150 reload validated test
specification and content from exam resource file 120, step 1543.
If the test has already started, plugins retrieve examination
information from exam instance file 120, step 1541. Plugins 150
then reload the validated test specification and content from exam
resource file 120, step 1543. Test driver 110 then delivers the
exam to the examinee, step 1545.
[0205] B. Plugin Life Cycle
[0206] FIG. 32 illustrates the life cycle of plugin 150 from test
production to test delivery, denoted generally by reference numeral
1420. Dashed vertical line 1422 divides the plugin life cycle 1420
into a test production cycle, to the left of dashed vertical line
1422, and a test delivery cycle, to the right of dashed vertical
line 1422. The test production cycle occurs only occasionally when
new plugins 150 are developed to satisfy the requirements of a
client. The test delivery cycle occurs whenever the test is
delivered to the examinee, for example, daily.
[0207] Exam source files 130, of which data files 132 and XXL files
134 are shown, contain every aspect of the test as written by the
test publisher. In step I, XXL compiler 140 reads from XXL files
134 and interprets instructions that call for the use of a plugin
150. Plugin 150 is identified in the XXL test definition language
by both a name and a program identification ("prog ID"). When XXL
compiler receives the prog ID from XXL files 134, XXL compiler
knows that a plugin 150 is required to complete the compilation of
exam source files 130.
[0208] Not all of the possible types of plugins 150 are required to
build any one test. Also, more than one plugin 150 is implemented
for a specific type. In the above example, two navigation plugins
162 and two item plugins 156 are defined. XXL compiler 140 reads
information from exam source files 130 using IStream interface 340,
iNode interface 1424, which is the Microsoft interface used to
access a node of an XML document in the document object model
("DOM"), and IStreamVB interface 348. XXL compiler 140 instantiates
the requested plugin 150 using, for example, the call
CoCreateInstance( ). CoCreateInstance( ) creates a single,
uninitialized object of the class associated with a specified
CLSID, using a prog ID that has been converted into the CLSID.
[0209] If the data referring to plugin 150 has been customized by
the test developer, XXL compiler 140 may not recognize the new
data. Therefore, XXL compiler 140 passes the data directly to
plugin 150 and plugin 150 loads the data into a private memory (not
shown). In one embodiment, the private memory is internal to plugin
150, and in another embodiment, the private memory is external to
plugin 150. Plugin 150 can then validate the data using the XXL
schema. If the data is invalid, plugin 150 reports the error. In an
alternative embodiment, plugin 150 can validate the data using an
XML document type definition ("DTD"). A DTD is a formal description
in XML Declaration Syntax of a particular type of document. Similar
to a schema, a DTD sets out what names are to be used to the
different types of elements, where they may occur, and how they all
fit together. However, the XXL schema is preferred for validation
since schemas are easier to read than a DTD and are very
flexible.
[0210] If plugin 150 declares that the data is valid, XXL compiler
140 prepares a POLESS storage object 300 in exam resource file 120
to which plugin 150 saves the data at a command from XXL compiler
140, in step II. As described previously, XXL compiler 140
determines where the data from plugin 150 is to be saved in exam
resource file 120 and creates the appropriate storage location. The
name, CLSID, and data associated with plugin 150 is stored in
plugins branch 900 in exam resource file 120 (FIG. 20). Plugin 150
implements IPersistResource interface 192 to store the data to exam
resource file 120. Data storage 906 stores, for example, the data,
for example, as either a stream, set of data, or as a storage
element if plugin 150 implements either IPersistResourceStream
192a, IPersistResourceSet interface 192b, or IPersistResourceStore
interface 192c, respectively. Data storage 908 stores, for example,
the data as a stream of data if plugin 150 implements
IPersistResourceStream interface 192a. Plugin 150 can choose the
format used to store the data into exam resource file 120. Steps I
and II are repeated until exam source files 130 are completely
compiled and exam resource file 120 is completely populated with
the compiled test information.
[0211] The compile sequence of a plugin 150, as shown in steps I
and II in FIG. 32, are illustrated in greater detail in FIG. 33.
Plugin compile sequence 1430 begins as XXL compiler 140 asks plugin
150 to validate the information from exam source files 130 that
pertain to plugin 150 using IPlugin::ValidateSource( ) call 1432,
in step I. Plugin 150 validates whether or not the data received
from exam source files 140 is correctly formatted based on the XXL
schema. If the data is not valid, plugin throws a structured COM
error. Plugin 150 does not validate that all required source
elements are present, but rather, that what is present is correctly
formatted.
[0212] Step 1I contains two steps, indicated as step IIa and IIb.
In step IIa, XXL compiler 140 creates the appropriate storage
element in exam resource file 120 using POLESS object 300. The
storage element type is determined based on the type of
IPersistResource interface 192 that plugin 150 implements, for
example: IPersistResourceStream interface 192a; IPersistResourceSet
interface 192b; or IPersistResourceStore interface 192c. XXL
compiler 140 then calls IPersistResource*::Save( ) call 1434 for
the appropriate IPersistResource interface. Plugin 150 saves the
compiled information from exam source files 130 to exam resource
file 120 through the POLESS object 300 passed by XXL compiler 140.
In step IIb, XXL compiler 140 instructs plugin 150 to unload, or
flush, its content using Unload( ) call 1436. As stated previously,
steps I, IIa, and IIb are repeated until all of exam source files
130 is compiled.
[0213] Step VI, which is shown as steps VIa and VIb, concerns
amalgamation of exam resource file 120. Amalgamation enables data
for a specific plugin to exist virtually as one storage location
even if the data appears at different locations within the storage
hierarchy. Amalgamation can be performed on exam resource file 120
if plugin 120 has implemented either IPersistResourceSet interface
192b or IPersistResourceStore interface 192c which storing data to
exam resource file 120. In step VIa, XXL compiler 140 amalgamates
one to three storage elements in exam resource file 120 and passes
the amalgamated POLESS object to plugin 150 using
IPersistResource*::ValidateResource( ) call 1438. Plugin 150
determines whether or not the amalgamated POLESS object creates a
complete and valid set. Plugin 150 throws a structured COM error if
the amalgamated POLESS object does not create a complete and valid
set. In step VIb, XXL compiler 140 instructs plugin 150 to unload,
or flush, its content using Unload( ) call 1440. Steps VIa and VIb
are interspersed among steps I, IIa, and IIb cycles and can also
occur multiple times during the compilation of exam source files
130. Amalgamation is described in greater detail, in U.S. Patent
Publication No. 20030129573, entitled "EXTENSIBLE EXAM LANGUAGE
(XXL) PROTOCOL FOR COMPUTER BASED TESTING," incorporated herein by
reference.
[0214] Referring again to FIG. 32, during the test delivery cycle,
test driver 110 reads the test specifications stored in exam
resource file 120 through POLESS objects 300. Test driver 110 reads
information from exam resource file 120 through POLESS objects 300
in order to retrieve the encrypted, compressed, and structured
elements within exam resource file 120. When the XXL test
definition language calls a plugin 150 by a prog ID, as described
previously, test driver 110 instantiates the plugin 150 that was
called, in step III. Test driver 110 provides the POLESS object 300
from exam resource file 120 and plugin 150 initializes itself from
the POLESS object 300, for example, data storage 906 or data
storage 908 stored under name attribute storage 902, using the
appropriate IPersistResource interface 192. The information loaded
into plugin 150 is the same information as was stored into exam
resource file 120 by plugin 150 during the test production cycle
(step II). Since plugin 150 chose the storage format used to store
the information into exam resource file 150, plugin 150 can always
read the information from exam resource file 150, giving plugin 150
complete flexibility. Test driver 110 need not be able to read the
information that is used by plugin 150. Therefore, any
customizations to the test facilitated by plugin 150 does not
require any changes to test driver 110. The test then progresses
with plugin 150 enhancing the functionality of test driver 110
based on the new requirements from the client.
[0215] Periodically, based on a request either from test driver 110
or from plugin 150, the state of all running objects will save to
exam instance file 170, which is a unique file for each examinee,
indicating the progress and the status of the test for that
examinee. Test driver 110 asks plugin 150 if plugin 150 is "dirty,"
meaning that plugin 150 is storing has some updated examination
state information. For example, when the examinee selects
distractor A on a multi-choice item, item plugin 156, in this case,
becomes dirty. If plugin 150 is dirty, test driver 110 provides
plugin 150 a POLESS object 300 in exam instance file 170 and plugin
saves the examination state information to exam instance file 170
using IPersistInstance interface 196, in step IV. For example, item
plugin 156 saves the examinee's answer to item plugin storage 1254
or to item plugin storage 1255 (FIG. 26). Item storage 1254 stores,
for example, the data as either a set of data or as a storage
element if item plugin 156 implements either IPersistInstanceSet
interface 196b or IPersistInstanceStore interface 196c,
respectively. Item storage 1255 stores, for example, the data as a
stream of data if item plugin 156 implements IPersistInstanceStream
interface 196a.
[0216] Step V occurs if the test is interrupted, for example,
because of a power failure, and the test needs to restart. When
test driver 110 is required to return to a particular operation
state, test driver 110 reads the examination state information from
exam instance file 170. Plugin 150 is provided the storage object
containing the state of plugin 150 as saved in step IV using
IPersistInstance interface 196. Using the previous example, item
plugin 156 retrieves its state information from item plugin storage
1254 or for item plugin storage 1255. Plugin 150 is able to become
operational from the retrieved state information, enabling a
restart of the test from the point at which the test was
interrupted.
[0217] The delivery sequence of a plugin 150, as shown in steps II,
IV, and V in FIG. 32, are illustrated in greater detail in FIGS.
34A, 34B, 34C, and 34D. As seen in FIG. 34A, delivery sequence 1520
particularly relates to visible plugins 150, e.g., display plugin
152, helm plugin 154, and item plugin 156. Step III contains
sub-steps labeled IIIa-IIIb. Plugin delivery sequence 1520 begins,
in step 111a, when the current delivering presentation requests its
template to activate with cTemplate::Activate( ) call 1524.
Activate( ) call 1524 is activated when the examinee navigates on
the test using a helm navigation control activated by helm plugin
154. IContainerNotifyHelm interface 206 allows helm plugin 154 to
request navigation from test driver 110. IContainerNotifyHelm
interface 206 sends Activate( ) call 1524 to cTemplate class 236 in
test driver 110 (see FIG. 8).
[0218] In step 111b, cTemplate class 236 in test driver 110 uses
IPlugin::Load( ) call 1526 to set the core object references from
test driver 110 into the plugin 150 being delivered. The core
object references include IContainerNotify interface 200, the cExam
class (not shown), and the IAppointment interface 176, which passes
information regarding the examinee and appointment to plugin
150.
[0219] Step V, which is interspersed with step III, occurs only if
the test is interrupted and plugin 150 loses state. cTemplate class
236 in test driver 110 uses IPersistInstance*::Reload( ) call 1528
to call on the reload method of exam instance file 170. Exam
instance file 170 reloads plugin 150, through IPersistInstance
interface 192, for example, IPersistInstanceSet 192b, with the
state saved to the appropriate storage location in exam resource
file 170 (see FIG. 26).
[0220] Step IIIc is performed for both initial delivery of plugin
150 and during restart of the test, in conjunction with step V.
cTemplate class 236 in test driver 110 uses
IPersistResource*::Load( ) call 1530 to call on the load method of
exam resource file 120. Exam resource file 120 loads plugin 150,
through IPersistResource interface 192, for example
IPersistResourceSet interface 192b, with the test specification and
content from the appropriate storage location in exam resource file
120. Plugin 150 is loaded with test specification and content from
exam resource file 120 when being initially delivered to the
examinee. Plugin 150 is also loaded with test specification and
content from exam resource file 120 and with examination state
information from exam instance file 170, as described above, when
the test has been interrupted and plugin 150 must recover
state.
[0221] After plugin 150 is properly loaded, cTemplate class 236 in
test driver 110 uses, I*::PresentationStarting( ) call 1532
(continued in FIG. 34B) to inform visible plugin 150 that the
presentation is starting, in step 111d. I*::PresentationStarting( )
call 1532 is made to any visible plugin 150 being used in the
presentation on the appropriate interface, for example: IDisplay
interface 169a, IItem interface 169c, or IHelm interface 169b. For
example, an IItem::PresentationStarting( ) call is used for item
plugin 156. cTemplate class 236 then instruct visible plugins 150
to display using IOleObject::DoVerb(Show, . . . ) command 1534,
step IIIe. IOleObject interface 1522 is the Active Document
interface used to implement the Active Document presentation.
IOleObject interface 1522 is the combination of the Active Document
interfaces described in conjunction with FIG. 7. After instructing
visible plugins 150 to display, test driver 110 awaits notification
from each visible plugin 150 that the specific visible plugin 150
has successfully shown. Visible plugins 150 call back to test
driver 110 using IContainerNotify::Activated( ) call 1536, step
IIIf (continued in FIG. 34B). Now, the presentation is started and
active such that the examinee can interact with the
presentation.
[0222] The deactivation of the presentation begins with a request
from the helm for navigation. For example, if the examinee has
finished a question and wishes to move on to the next question on
the next presentation, the examinee can choose the "NEXT" button on
the helm. The navigation request is sent from IHelm interface 169b,
which receives the request from the examinee, to test driver 110
using IContainerNotifyHelm interface 206. As seen in FIG. 34D, the
request is made using IContainerNotifyHelm::Request- -Move( ) call
1538, step IIIg. Test driver 110 then asks each item plugin 156
being used in the presentation template if the examinee is allowed
to leave the current presentation and to proceed to the next
presentation. The query is made using IItem::bProceed( ) call 1540,
step IIIh. If all item plugins 156 respond in the affirmative, test
driver 150 passes the navigation request to navigation plugin 162,
which is an invisible plugin 150. Test driver 110 passes the
request using INavigate::RequestMove( ) call 1542, step IIIl.
Navigation plugin 162 determines the resultant location of the
requested navigation. In FIG. 34, for example, navigation plugin
162 determines the section of the test to which the examinee will
proceed using ISection::ChildNext( ) call 1544, step IIIj.
[0223] The active presentation then instructs the template to
deactivate using cTemplate::Deactivate( ) call 1546, step IIIk
(continued in FIG. 34C). Referring back to FIG. 34D, template class
236 in test driver 110 requests that visible plugins 150 hide from
the Active Document using IOleObject::DoVerb(Hide, . . . ) call
1548, step IIIl. cTemplate class 236 in test driver 110 informs
visible plugins 150 that the current presentation is ending using
I*::PresentationEnding( ) call 1550, step IIIm. For example,
cTemplate informs helm plugin 154 that the current presentation is
ending using the IHelm::PresentationEnding( ) call.
[0224] Step IV, which contains sub-steps IVa-c, is the process to
save plugin state data to exam instance file 170. Test driver 110
requests the "dirty" state of plugin 150 to determine whether
plugin 150 is storing any state information that would be necessary
if the test were to be interrupted. Test driver 110 uses
IPersistInstance*::IsDirty( ) call 1552 to make the request, step
IVa. For example, test driver 110 uses IPersistInstanceSet::IsDirty
call 1552 if the state data is a property set. If plugin 150 is
storing state data that is not already stored in exam instance file
170, IPersistInstance*::IsDirty( ) call 1552 returns true. If
plugin 150 is "dirty", test driver 110 instructs plugin 150 to save
the state data to exam instance file 170 in the POLESS object
provided (FIG. 26) using IPersistInstance*::Save( ) call 1554, step
IVb. Finally, test driver 110 instructs plugins 150 to unload all
objects using IPlugin::Unload( ) call 1556, step IVc.
[0225] VI. Network Environment for a Computer-Based Testing
System
[0226] A description of a network environment for a computer-based
testing system according to the present invention including a test
driver that controls delivery of a computer-based test over a
networked environment by caching test components for delivery to a
test candidate in order to facilitate a uniform testing environment
for at least one or more concurrent test candidates is provided.
FIG. 35 is a block diagram illustrating an example of a network
environment for a computer-based test system according to the
present invention.
[0227] With reference to FIG. 35, the computer-based testing system
of the present invention includes a test management system,
including a Web certified proctor management site 3160 and secure
ID server 3150, for identifying proctors of the computer-based
test; a test proctor certification system, including Web
eligibility management site 3190 and GEE server 3180, for
certifying proctors for administering the computer-based test; a
test registration system to enable candidates to request an
appointment to take a test, including Web registration site 3200 to
allow appointments to be reserved via the Internet, scheduling
middleware 3170 to process the candidates request to take the test,
schedule interface service 3220 which provides the scheduled
appointment data to candidate workstation 3000 to identify the
candidate and to verify the candidate's credentials, an ecommerce
system 3210 for registering test candidates for the computer-based
test and for collecting and/or processing any payments associated
with scheduling and delivering the computer-based test; and a test
analysis system, including results collection server 3230 for
aggregating results from all delivered tests, a data warehouse 3240
for storing and allowing access to such test results, and a results
psychometric system 3250 for monitoring candidate responses to test
items, maintaining the composition of the computer-based tests, and
to enable item response analysis and reports to be generated and
distributed.
[0228] The network environment as shown in FIG. 35 further includes
a computer-based test production system, including test publisher
system 3010 for authoring a computer-based test and producing exam
source files (previously described) which store test specification
and content; test packaging system 3020 for retrieving, validating
and compiling the exam source files of the computer-based test into
an exam resource file (previously described); and source server
3030 for storing and managing versions of the compiled exam
resource file and any additional corresponding test components
comprising the computer-based test. The network environment also
includes distribution servers for facilitating computer-based
testing, including application deployment servers 3040, item cache
servers 3050 and plugin cache servers 3060, connected to source
server 3030 via a wide area network (i.e., an interconnected system
of networks), and connected to candidate workstation 3000 via a
local access network. The local access network can include LAN,
xDSL access network, cable access network, or wireless access
network. From source server 3030, the test components are extracted
from the exam resource file of the computer-based test and deployed
to the distribution servers. Application deployment servers 3040
store the test driver application and the exam resource file,
containing the core test specifications of the computer-based test,
for distribution to candidate workstation 3000. Item cache servers
3050 store test items extracted from the exam resource file. Plugin
cache servers 3060 store plugins extracted from the exam resource
file. The network environment further includes any number of test
candidate workstations at a multiplicity of locations to which the
computer-based test is scheduled to be delivered. Thus, the
distribution servers may be clustered for parallel processing, load
balancing and fault tolerance to support a varied volume of at
least one or more concurrent test candidates.
[0229] From application deployment servers 3040. the test driver
application for controlling delivery of the computer-based test may
be downloaded for setup on candidate workstation 3000. The test
driver application 3070 may be stored on a computer readable
medium, such as a hard drive or other magnetic medium, connected to
candidate workstation 3030. However, test components of the
computer-based test, including the exam resource file, test items
and plugins (all of which were previously described), are stored in
random access memory (RAM) to prevent unauthorized copying or
manipulation of the computer-based test, thereby assuring the
integrity of the test.
[0230] Test driver application 3070 includes session manager 3080
for managing the computer-based testing session, having
authentication layer 3090 for authenticating proctors of the
computer-based test, event locator candidate credential interface
3100 for certifying test candidate eligibility to use the
computer-based test and Unified Test Driver (UTD) core 3110 for
controlling delivery of the computer-based test to candidate
workstation 3000. UTD core 3100 controls item cache controller
3120, plugin cache controller 3130 and browser presentation layer
3140. Item cache controller 3120 stores test items retrieved from
item cache servers 3040 in item cache 4360 (FIG. 36), encrypted
memory mapped paged RAM on candidate workstation 3000, for delivery
to the test candidate. Plugin cache controller 3130 stores plugins
retrieved from plugin cache servers 3160 in plugin cache 4390 (FIG.
36), memory mapped paged RAM on candidate workstation 3000, for use
by UTD core 3100. Browser presentation layer 3140 serves the
computer-based test on candidate workstation 3000 in accordance to
the exam resource file retrieved from application deployment
servers 3040.
[0231] VII. Caching Architecture for the Computer-Based Testing
System
[0232] In computer-based testing, a test may be delivered to a
candidate workstation using two delivery modes: a disconnected mode
(e.g., non-networked) or a connected mode (e.g., networked). A
disconnected mode is a traditional delivery mode in which every
element required to administer the computer-based test is stored on
the test candidate workstation before the computer-based test is
initiated. Thus, there is no need to monitor the testing
environment to adjust delivery of the computer-based test over a
network environment and no need to implement a caching architecture
for a network environment. In contrast, a connected mode is a
non-traditional delivery mode in which core elements of the
computer-based test are stored on the test candidate workstation
and additional test components are retrieved during computer-based
testing from distribution servers over a network environment. While
using the connected mode provides many advantages, such as,
flexibility in administering computer-based tests to test
candidates located in multiple locations, the network environment
introduces environment variables that are not controllable by a
test administrator without great cost. Thus, in order to provide a
uniform testing environment to a varied volume of at least one or
more concurrent test candidates located in multiple locations, a
computer-based system must adjust delivery of a computer-based test
in order to compensate for variance in the network environment.
[0233] A description of a caching architecture for a computer-based
testing system of the present invention including a test driver
that controls delivery of a computer-based test over a networked
environment by caching test components for delivery to a test
candidate in order to facilitate a uniform testing environment for
at least one or more concurrent test candidates is provided. FIG.
36 is a block diagram of a caching architecture for a
computer-based test system according to the present invention.
[0234] As shown in FIG. 36, test driver application 3070 includes
Web service interface 4400, having authentication module 4410. Web
service interface 4400 facilitates network communications between
candidate workstation 3000 and the distribution servers.
Authentication module 4410 authenticates the test components
retrieved from the distribution servers. Web service interface 4400
further logs the transmission details of each request and response
transmitted between candidate workstation 3000 and the distribution
servers, which includes, but is not limited to, for example, the
time at which candidate workstation 3000 sends a request to a
distribution server, the time at which a distribution server
receives the request, the time at which a distribution server sends
a response to candidate workstation 3000 and the time at which
candidate workstation 3000 receives the response. Such details
further include, for example, error messages issued by the network,
error messages issued by the distribution servers, the number of
retries by candidate workstation 3000 to send a request to the
distribution servers, the number of retries by candidate
workstation 3000 to obtain a response from the distribution servers
and the size of each message or test components transmitted.
[0235] Test driver application 3070 further includes item request
interface 4340, plugin request interface 4370, request processor
4310, decryption module 4320, decompression module 4330, item
request module 4350, plugin request module 4380, cache controller
4400, item cache 4360 and plugin cache 4390. Test driver
application 3070 sends requests to retrieve test components via
item request interface 4340 and plugin request interface 4370.
Request processor 4310 processes requests for test components
initiated by test driver application 3070 and delivery of test
components retrieved from the distribution servers to test driver
application 3070. Item request module 4360 facilitates retrieval of
test items from item cache servers 3040. Plugin request module 4380
facilitates retrieval of plugins from the plugin cache servers
3060. Cache controller 4400 manages the storing of test components
in item cache 4360 and plugin cache 4390. Item cache 4350 stores
test items retrieved from item cache servers 3040. Plugin cache
4390 stores test plugins retrieved from plugin cache servers 3060.
Decryption module 4320 decrypts test components that have been
encrypted for preserving the integrity of the computer-based test.
Decompression module 4330 decompresses test components that have
been compressed for transmitting over the network environment.
[0236] Descriptions of example caching operations of a
computer-based testing system of the present invention including a
test driver that controls delivery of a computer-based test over a
networked environment having the caching architecture are provided.
Because the computer-based test comprises cacheable objects, it is
possible to download only selected test components from the
distribution servers to the candidate workstation for delivering a
current test section in accordance to the test specifications.
Thus, it is possible for a test candidate to initiate a
computer-based test prior to all test components being downloaded
to the candidate workstation.
[0237] FIG. 37A is a flow chart of a method of caching test items
with respect to the caching architecture according to the present
invention. With reference to FIG. 37A, when test driver application
3070 requires a test item, test driver application 3070 via item
request interface 4340 instructs request processor 4310 to retrieve
the test item at steps S3710A and S3715A. Request processor 4310
verifies whether the test item is available in item cache 4360 at
step S3720A. If the requested test item is available locally (e.g.,
hit), request processor 4310 retrieves the test item from item
cache 4360 at step S3755A. If necessary, decompression module 4330
decompresses the test item at step S3750A and decryption module
4320 decrypts the test item at step S3765A. Request processor 4310
returns the test item to test driver application 3070 at step
S3770A. However, if the test item is not available locally (e.g.,
miss), item request module 4350 requests the test item from item
cache servers 3050 via Web service interface 4400 at steps S3725A
and S3730A. Web service interface 4400 requests the test item from
item cache server 3050 at step S3730A. Item cache server 3050 or
the source server 3030 returns the requested test item at step
S3735A. Authentication module 4410 authenticates the returned
requested test item at step S3740A. Item cache controller 3120
requests storage instructions from cache controller 4400 at step
3745A and accordingly stores the returned requested test item in
item cache 4360 at a step S3750A. Request processor 4310 retrieves
the test item from item cache 4360 at step S3755A. If necessary,
decompression module 4330 decompresses the test item at step S3760A
and decryption module 4320 decrypts the test item at step S3765A.
Request processor 4310 delivers the test item to test driver
application 3070 at step S3770A.
[0238] A similar process occurs when test driver application 3070
requires a plugin. FIG. 37B is a flow chart of a method of caching
plugins respect to the caching architecture according to the
present invention. With reference to FIG. 37B, when test driver
application 3070 requires a plugin, test driver application 3070
via plugin request interface 4370 instructs request processor 4310
to retrieve the plugin at steps S3710B and S3715B. Request
processor 4310 verifies whether the plugin is available in plugin
cache 4390 at step S3720B. If the requested plugin is available
locally (e.g., hit), request processor 4310 retrieves the plugin
from plugin cache 4390 at step S3755B. If necessary, decompression
module 4330 decompresses the plugin at step S3760B and decryption
module 4320 decrypts the plugin at step S3765B. Request processor
4310 returns the plugin to test driver application 3070 at step
S3770B. However, if the plugin is not available locally (e.g.,
miss), plugin request module 4370 requests the plugin from plugin
cache servers 3060 via Web service interface 4400 at steps S3725B
and S3730B. Web service interface 4400 requests the plugin from
plugin cache server 3060 at step S3730B. Plugin cache server 3060
or the source server 3030 returns the requested plugin at step
S3735B. Authentication module 4410 authenticates the returned
requested plugin at step S3740B. Plugin cache controller 3130
requests storage instructions from cache controller 4400 at step
S3745A and accordingly stores the returned requested plugin in
plugin cache 4390 at a step S3750B. Request processor 4310
retrieves the plugin from plugin cache 4390 at step S3755B. If
necessary, decompression module 4330 decompresses the plugin at
step S3760B and decryption module 4320 decrypts the plugin at step
S3765B. Request processor 4310 delivers the plugin to test driver
application 3070 at step S3770B. Moreover, a cache cleaning
algorithm may be employed to retire test items and/or plugins when
one or more predetermined conditions are satisfied, e.g., when a
predetermined amount of time expires after the test item and/or the
plugin is added to item cache 4360 or plugin cache 4390,
respectively.
[0239] Caching of a computer-based test for delivery to candidate
workstation 3000 is facilitated in accordance to the changing
testing environment during computer-based testing reflected by
monitoring of candidate progress, candidate performance, network
bandwidth, network latency and server response, among other
environmental variables, during computer-based testing. With
reference to FIG. 36, test driver application 3070 further includes
stimuli processor 4400, cache controller 4410, candidate
performance monitor 4420, candidate progress monitor 4430, network
latency monitor 4440, network bandwidth monitor 4450 and server
response monitor 4460. In response to changes in the testing
environment, stimuli processor 4410 adjusts the source for
retrieving test components or the volume of test components to
store in cache memory on candidate workstation 3000 and instructs
cache controller 4410 accordingly. Environment monitoring means as
shown in FIG. 36 include, but are not limited to, for example,
candidate progress monitor 4430, which measures the rate at which
the test candidate is answering test items; candidate performance
monitor 4420, which measures test candidate competency; network
bandwidth monitor 4450, which measures data transfer speed between
candidate workstation 3000 and distributions servers; network
latency monitor 4440, which measures delay times between candidate
workstation 3000 and distributions servers caused by the network;
and server response monitor 4460, which measures the delay times
between candidate workstation 3000 and distributions servers when
delay is caused by the server.
[0240] Descriptions of caching operations of a computer-based
testing system according to the present invention is provided.
Generally, stimuli processor 4410 periodically initiates an inquiry
to candidate progress monitor 4430, candidate performance monitor
4420, network bandwidth monitor 4450, network latency monitor 4440
and server response monitor 4460 during computer-based testing. The
results of each monitor are returned to stimuli processor 4410.
Based these results, stimuli processor 4410 adjusts either the
source of test components or the volume of test components being
cached for delivery of the computer-based test and cache controller
4400 accordingly. Examples of the operations of the testing
environment monitors candidate progress monitor 4430, candidate
performance monitor 4420, network bandwidth monitor 4450, network
latency monitor 4440 and server response monitor 4460 are now
described.
[0241] For example, candidate progress monitor 4430 measures the
test candidate's rate of progress in answering test items during
computer-based testing for maintaining availability of test items.
FIG. 39A shows a flow chart of the operation of candidate progress
monitor 4430. Stimuli processor 4410 initiates an inquiry to
candidate progress monitor 4430 at step S3800A. Candidate progress
monitor 4430 retrieves the number of test items allotted to the
current test section and the time allotted to each test item, which
are stored in the exam resource file (described previously) on
candidate workstation 3000 at step S3810A. Candidate progress
monitor 4430 retrieves the number of test items answered by the
test candidate and the answer time used by the test candidate for
answering each test item, which are stored in the exam instance
file (described previously) on candidate workstation 3000 at step
S3815A. Candidate progress monitor 4430 then calculates the rate at
which the test candidate answers test items at step S3820A and
returns the number of test items allotted to the current test
section, the number of test items answered by the test candidate in
the current test section and the answer rate to stimuli processor
4410 at step S3825A for determining whether a sufficient pool of
test items are available to the test candidate during
computer-based testing. Based on these results, stimuli processor
4410 calculates the number of test items remaining in the current
test section for delivery to the test candidate at S3830A. Stimuli
processor 4410 then retrieves the number of test items stored in
item cache 4360 at step S3835A and calculates the number of test
items remaining to be cached in the current test section for
delivery to the test candidate at step S3840A. Based on the answer
rate and the number of test items remaining to be cached, stimuli
processor 4410 determines whether it has become necessary to
retrieve additional test items for caching at step S3845A. When it
has become necessary to retrieve additional test items, stimuli
processor 4410 instructs cache controller 4400 accordingly at step
S3850A. Otherwise, monitoring continues at step S3855A.
[0242] In another example, candidate performance monitor 4420
measures the test candidate's competency in answering test items
during computer-based testing for maintaining availability of
suitable test items. FIG. 39B shows a flow chart of the operation
of candidate performance monitor 4420. Stimuli processor 4410
initiates an inquiry to candidate performance monitor 4420 at step
S3800B. Candidate performance monitor 4420 retrieves the number of
test items answered in the current test section, the competency
level of each test item and the scoring of each test item, which
are stored in the exam instance file (described previously) on the
candidate workstation at step S3810B. Candidate performance monitor
4420 then calculates the competency level of the test candidate at
step S3815B and returns the candidate competency level to stimuli
processor 4410 at step S3820B for determining whether a sufficient
pool of suitable test items are available to the test candidate
during computer-based testing. Stimuli processor 4410 then
retrieves the number of test items of the candidate competency
level stored in item cache 4360 at step S3825B and calculates the
number of test items of the candidate competency level remaining to
be cached in the current test section for delivery to the test
candidate at S3830B. Based on the candidate competency level and
the number of test items of the candidate competency level
remaining to be cached, stimuli processor 4410 determines whether
it has become necessary to retrieve additional test items of the
current competency level for caching at step S3835B. When it has
become necessary to retrieve additional test items of the candidate
competency level, stimuli processor 4410 instructs cache controller
4400 accordingly at step S3840B. Otherwise, monitoring continues at
step S3845B.
[0243] A further example is network bandwidth monitor 4450 which
measures the speed of data transfer between candidate workstation
3000 and a distribution server for maintaining timely availability
of test items. FIG. 39C shows a flow chart of the operation of
network bandwidth monitor 4450. Stimuli processor 4410 initiates an
inquiry to network bandwidth monitor 4450 at step S3800C. For each
exchange between candidate workstation 3000 and a distribution
server, network bandwidth monitor 4450 retrieves from logs
generated by Web service interface 4400 the time a request is sent
by candidate workstation 3000 to a distribution server, the time
the request is received by the distribution server, the size of the
request message, the time a response is sent by the answering
distribution server, the time the response is received by candidate
workstation 3000 and the size of the response message at step
S3810C. Based on these variables, network bandwidth monitor 4450
calculates the data transfer speeds between candidate workstation
3000 and distribution servers at step S3015C and returns the data
transfer speeds to stimuli processor 4410 at step S3820C for
determining frequency of requests to retrieve test components and
size of test components being transferred. Based on these results,
stimuli processor 4410 calculates whether network bandwidth is
growing or deteriorating at step S3825C and then stimuli processor
4410 instructs cache controller 4400 accordingly at step S3830C.
For example, when network bandwidth is narrowing, frequency of data
transfer may be increased and size of test components to be
transferred may be decreased to compensate for loss of data
transfer speed at step S3835C. Otherwise, monitoring continues at
step S3840C.
[0244] An additional example, network latency monitor 4440 measures
the delay in data transmission time between candidate workstation
3000 and the distribution servers caused by the network for
re-establishing connectivity during computer-based testing. FIG.
39D shows a flow chart of the operation of network latency monitor
4440. Stimuli processor 4410 initiates an inquiry to network
latency monitor 4440 at step S3800D. For each exchange between
candidate workstation 3000 and a distribution server, network
latency monitor 4440 retrieves from logs generated by Web service
interface 4400 the time a request is sent by candidate workstation
3000 to a distribution server, the time the request is received by
the distribution server, the size of the request message, the time
a response is sent by the answering distribution server, the time
the response is received by candidate workstation 3000, the size of
the response message, the number of transmission retries and any
network error messages received at step S3810D. Based on these
variables, network latency monitor 4440 calculates delay times
between candidate workstation 3000 and distribution servers caused
by the network at step S3815D and returns the delay times to
stimuli processor 4410 at step S3820D for determining the state of
network connectivity. Stimuli processor 4410 retrieves a
predetermined tolerance threshold from the exam resource file
(described previously) at step S3825D and determines the rate delay
times are approaching the tolerance threshold at step S3830D. Delay
times approaching within a predetermined range of the tolerance
threshold indicates that network connectivity failure is imminent.
Prior to such failure, stimuli processor 4410 determines whether a
sufficient number of test components are cached for delivery to the
test candidate while the test driver reconnects to a redundant
network in the background at step S3835D and instructs cache
controller 4400 accordingly at step S3840D. Otherwise, monitoring
continues at step S3845D.
[0245] In another example, server response monitor 4460 measures
the delay in data transmission time between candidate workstation
3000 and the distribution servers caused by the distribution
servers for maintaining accessibility to a source for test
components during computer-based testing. FIG. 39E shows a flow
diagram of the operation of server response monitor 4460. Stimuli
processor 4410 initiates an inquiry to server response monitor 4460
at step S3800E. For each exchange between candidate workstation
3000 and a distribution server, server response monitor 4460
retrieves from logs generated by Web service interface 4400 the
time a request from candidate workstation 3000 is received by a
distribution server, time a response is sent by the answering
distribution server, the number of retries and any server error
messages received at step S3810E. Based on these variables, server
response monitor 4460 calculates delay times between candidate
workstation 3000 and a distribution server caused by the servers at
step S3815E and returns the delay times to stimuli processor 4410
at step S3820E for determining the state of server accessibility.
Stimuli processor 4410 retrieves a predetermined tolerance
threshold from the exam resource file (described previously) at
step S3825E and determines the rate delay times are approaching the
tolerance threshold at step S3830E. Delay times approaching within
a predetermined range of the tolerance threshold indicates that
server accessibility is limited and stimuli processor 4410
instructs cache controller 4400 accordingly at step S3835E.
Otherwise, monitoring continues at step S3840E.
[0246] The present invention is not limited to the embodiment
described herein. For example, the test driver application and
cacheable test components may be stored on the same distribution
servers for delivery to test candidates. In addition, the
distribution servers, in groups or singly, can be located in any
number of remote locations. Furthermore, the testing environment
monitors can include other monitors not specifically described
herein. Thus, cacheable objects are used to expand functionality of
a test driver application that controls delivery of a
computer-based test to one or more test candidates over a dynamic
distributed network environment by adapting delivery of the
computer-based test in accordance to monitoring of testing
environment variables.
[0247] The many features and advantages of the invention are
apparent from the detailed specification, and thus, it is intended
by the appended claims to cover all such features and advantages of
the invention, which fall within the true spirit and scope of the
invention. Further, since numerous modifications and variations
will readily occur to those skilled in the art, it is not desired
to limit the invention to the exact construction illustrated and
described, and accordingly, all suitable modifications and
equivalence may be resorted to, falling within the scope of the
invention.
* * * * *