Asynchronous distance learning environment, Client-Server, event multicasting.
Focus and context
work describes a tool that can be used to build graphical organizers to
present asynchronous, distributed learning courses. The organizer tool
is integrated into a software suite entitled CmapTools that
utilizes a unique client-server architecture. The Organizer helps the
instructional designer organize a learning environment using a graphical
representation of topics, their sequences, and additional explanatory
information on their relationships. The organizer presents essential dependency
relationships among topics in a course, points the student to online instructional
content pertinent to the topic, and downloads the lesson content for the
student. The system tracks student progress through the learning environment.
This work describes the tools basic functionality, look and feel,
and presents an example of a learning environment organizer created with
rapidly evolving nature of technological economies and the sorts of work
they generate increasingly require people to be lifelong learners. Increasingly,
people are seeking to enhance their education while working full-time
jobs, which do not easily permit them to attend traditional face-to-face
classes. Simultaneously, the integration of computer-based networking,
computer-mediated instruction, and multimedia technology hold the promise
of improved distance learning environments. This integration, coupled
with the fact that the Internet has revolutionized the basic availability,
categorization, and searchability of instructional content, creates great
potential for asynchronous distance learning environments.
paper describes a network-based learning environment organizer software
program that offers support for asynchronous distance learning, anytime,
anywhere. The Organizer achieves much of its capabilities from its integration
into CmapTools, a knowledge modeling environment [1, 2, 3]
with a client-server architecture . CmapTools gains much of its capabilities
(which the Organizer exploits) from its own event multicasting virtual
machine, which, on the client side, was built on top of the JavaTM
Organizer helps the instructional designer organize a learning environment
using a graphical representation of topics, their sequences, and additional
explanatory information on their relationships. The designer can attach
tasks or activities to topics in the organizer and can choose from among
a variety of criteria for task completion. The organizer presents essential
dependency relationships among topics in a course, points the student
to online instructional content pertinent to the topic, and downloads
the content at the students request.
rest of this paper will discuss asynchronous, distance learning environments,
CmapTools, and the Organizer as it is integrated into CmapTools. It will
first present a brief overview of the benefits and drawbacks of asynchronous
distance learning environments. It will then discuss the basic architecture
of CmapTools a client-server model that allows the Organizer to
access online instructional content. It will discuss the basic features
and the look and feel of the Organizer itself. The paper will close with
a discussion of an example Organizer for an online course on the topic
of Managerial Decision Making.
Asynchronous Distance Learning Environments
distance learning environments have rapidly become widespread for post-secondary
education [5, 6, 7, 8]. They offer a variety of benefits such as efficient
and effective use of a students time. Most traditional classes meet
once or twice a week, and students only participate in those classes they
attend. With asynchronous distance learning classes, students may participate
many times per week, at their convenience. Students are also able to read
and carefully formulate responses to questions or discussions, attain
higher levels of participation, and create written records of their interactions
in the course . Other benefits include potentially simple evaluation
schemes, and cost effective educational delivery .
courses can utilize numerous facilities that are already available on
the World Wide Web, including the use of Web pages as course content,
asynchronous forms of communication such as electronic mail, listservers
and newsgroups, and synchronous forms of communication such as chat rooms
and videoconferencing . Some online courses are augmented with computer
programs such as Convene Software , SimulNet
, TopClass  and CODILESS . These programs
provide a variety of capabilities for synchronous and asynchronous distance
these capabilities, online asynchronous courses typically seek to emulate
traditional classroom methods of instruction, only at a distance. The
Organizer described in this work substantially augments the capabilities
of the standard Internet technologies and adopts a different approach
to distance learning that affords great flexibility to the designer and
the student. The Organizer gains much of its capabilities from its integration
with CmapTools, the topic of the next section.
CmapTools: Concept Mapping Software Toolkit
is a software suite that is in ongoing development at the Institute for
Human and Machine Cognition (IHMC), University of West Florida. This software
suite is built as a client-server system that enables distance learning
and collaboration over the Internet. Figure 1 illustrates the CmapTools
architecture (personal communication, Niranjan Suri).
1. The Client-Server Model of CmapTools.
system allows electronic instructional content in the form of concept
maps , text, graphics, audio and video to reside on machines that
are configured with the CmapTools server software. Any machine on the
network can be set up as a CmapTools server and can be used as a non-local
repository for these resources. Such servers can be accessed from any
machine with TCP/IP and the client software. The runtime system itself
supports storing resources on remote machines from the local machine that
is being used to edit the content. Other Web-based content such as Web
pages can also be accessed from the CmapTools client.
client software is organized around an additional software layer that
has been built on top of the JavaTM Virtual Machine. This layer,
called the "Core," provides synchronization and event multicasting
among a group of modules that work like plug-ins to provide the functionalities
of the system. When the software is loaded, the modules register the so-called
"Core" events that they will generate and handle with the Core.
As the software runs, individual modules detect Java events and convert
them to "Core" events. The Core multicasts these events, so
that each module that requires notification of the occurrence of a Core
event is informed that it occurred.
2 presents a graphic illustrating the structure of the client program,
including the various communications among the Core and the other modules.
The basic modules are: a network communications client, several modules
that allow for creation and editing of projects, modules that contain
the functionality of a concept map editor/browser, the Organizer modules,
a rule-based inference module that utilizes JESS (Java Expert System Shell)
, collaboration tools, a search module, and other utilities. These
modules can be included in various combinations in a system build to create
software that can be specialized for a variety of applications, including
the creation of the organizer that is described in this work.
2. The Core and modules that comprise the CmapTools client program.
4. The Learning Environment Organizer
section describes the organizers look-and-feel and basic functionality.
An Organizer takes the form of a graph (in the mathematical sense of the
word), with two different types of nodes, instructional topic nodes, called
place nodes, and explanation nodes that explain about the topics. The
place nodes have color codings to indicate student progress through the
course of instruction. The Organizer presents both a global (context)
view and a local (focus) view of the course structure, and a Display
Status Panel. These features will each be described in more detail
in the next sections. Figure 3 presents a view of an organizer pertaining
to a course in Data Structures.
(Click on the image for a larger view)
3. The Organizer in User mode, showing place and explanation nodes.
nodes correspond to the topics in the course. Explanation nodes elaborate
the relationships among the place nodes and have no adornments. Figure
3 depicts place nodes as those surrounded with shadowed boxes, populated
with icons, and containing a rectangle that color-codes the status of
the place. For example, Introduction to Data Structures, Linked
Lists, Arrays, Recursion, etc., are place
nodes. The place nodes are linked together by double lines that convey
prerequisite relationships. They have links to the instructional content
that can be used to learn about the topic under consideration and to perform
the tasks or activities associated with the topic. When the user clicks
on the icon that looks like a graph beneath the place, a pull-down menu
appears that presents links to online instructional content that is pertinent
to the topic. The other icons beneath the place nodes may be clicked to
access the tasks, assignments, activities, etc. that are associated with
the topics. These assignments may be rendered in text, in a video of the
instructor describing the assignment, or in other media the instructor
place nodes are color coded to indicate the student's progress through
the organizer. There are separate, configurable colors for completed nodes,
the current node, nodes for which the student is ready, and nodes for
which she or he is not yet ready. When a place is completed, the system
changes the color code of that place to the color that indicates completed
status and then determines which subsequent places are to be changed to
instructor can specify the criteria for completion of a topic. Several
possible alternatives have been identified and implemented. The instructor
may require a submission of a deliverable that must be evaluated before
indicating that the place is completed. The student could download a test
(true/false or multiple choice) that could be taken and graded on the
spot by an automated process, with the organizer updated immediately.
The place could be essentially optional or suggested, in which case the
student might be allowed to decide when to mark it and move on. The icon
on the left side of the place node indicates completion criteria for the
topic. The icon that looks like an envelope indicates that a submission
must be made to the instructor. The icon that looks like a smiling student
indicates that the user marks the topic completed when s/he is ready to
do so. The icon that looks like a text indicates that the student takes
a test to complete the topic.
The Context and Focus View.
context view of the organizer appears in Figure 3 as the floating palette
in the upper left corner of the window. A highly articulated organizer
with many topics and a large number of explanatory nodes can grow very
large and tangled, and does not fit in its entirety on a computer monitor.
A significant concern that the design of this software addresses is the
need of the user to see the entire organizer while still being able to
read a portion of the organizer. A basic focus and context scheme has
been chosen as an information visualization solution to this problem [17,
focus is the large rectangular component that fills most of the window.
It is resizable by resizing the entire window. When it is resized, the
rectangle in the context view resizes to maintain proportion with the
focus view. The focus contains the actual part that the user views.
The user can grab the blue rectangle in the context view and move it around
to move around the focus view. This mechanism is useful since it allows
scrolling horizontally vertically, or along arbitrary trajectories in
a single mechanism, rather than only horizontally or vertically through
two mechanisms, via scrollbars.
Display Status Panel.
3 illustrates the Display Status Panel, the small rectangular panel in
the top-center of the graphic, which allows subsets of the organizer network
to be shown or hidden. To ameliorate the potential problem of information
overload, nodes of any given status (completed, current, ready, not ready)
may be either shown or hidden. In addition, the explanation nodes may
be shown or hidden. The check boxes associated with a given node status
may be selected or deselected to show or hide that subset of the organizer.
The colors of the words indicating status in the Display Status Panel
correspond to the color codes associated with the nodes themselves. For
example, the word "completed" in the display status panel is
color-coded blue. As instructional places are completed, their color codings
are changed to blue.
explanatory nodes provide additional information about the place nodes
and can also be shown or hidden by the same mechanism. If they are shown,
the explanatory nodes elaborate the relationships among the place nodes
at the possible expense of a potentially very large amount of additional
information being displayed on the screen. If the explanation nodes are
hidden, the student has less advance knowledge of what will be encountered
at that place, but less clutter on the screen.
Login - registration and authentication.
can freely browse through the materials in the organizer at any time.
If they wish to work on a course with the organizer, they must first register
with the system and log on. Once the student has logged in, the system
either retrieves the progress record associated with the userid and the
organizer for which the logon occurred, or it creates a new progress record
for the given organizer and userid. The progress record contains information
on the student's progress, submissions of deliverables, whether the deliverables
have been graded, etc. When the student initiates the process of setting
a place to completed status, the system manages the process.
If the student has permission to update the status of a given place, the
system automatically updates the screen display and the student progress
separate application program (which is not part of this work) enables
the instructor to check assignments students have submitted. The application
the instructor uses checks the progress records of each student, looking
for ones that require evaluation and update. The progress record has a
field that indicates the need for the update. The instructor's software
checks the progress records for the students, determines which ones have
submission evaluations pending, and provides the capability to indicate
the results of the evaluation to the student.
An Example Organizer
MDM Organizer illustrated in Figure 4, was created in a collaborative
effort with the instructor of a graduate course on Managerial Decision
Making. The MDM Organizer is tightly coupled with a knowledge model that
was previously created using the knowledge modeling capabilities of CmapTools.
The Organizer presents the user with a clear depiction of the two major
threads of the course, regression and time-series models, and how these
are used to create forecasts. The organizer also presents explanatory
information on the types of analyses that can be performed with the various
(click on the
image for a larger view)
4. The MDM Organizer.
MDM organizer was created by making an initial mapping of topics, followed
by iterations between refining the topics and their sequences, and the
addition of the explanatory component. The designer of the MDM organizer
changed the organization substantially through the various iterations.
When the topics and explanations were stable, the completion modes for
the courses were mapped. This example utilizes the entire range of completion
criteria that the organizer provides. The locations of four tests and
a number of submissions to the instructor were identified and indicated
in the organizer. Many of the topics simply required the student to perform
an activity and then mark the topic completed.
entry points into the MDM model were fairly evident from the topics in
the organizer and the model itself. The links between these places were
mapped. Additional sources of information that resides on the World Wide
Web and is pertinent to the various topics were identified and linked
into the Organizer. Although this Organizer was viewed as a demonstration
of the capabilities of the tool, it is anticipated that it will be useful
for distance learning course delivery when additional components of the
system, such as the database management system for student progress records
6. Summary and Future Work
work describes a new approach to an online asynchronous distance learning
environment that is designed to deliver instructional content anytime,
anywhere. The Organizer is comprised of modules that are included in a
client-server application that enables the tool to retrieve online instructional
materials for the user of the system. The Organizer provides the user
with a graphical representation of topic sequences in the course, explanatory
information regarding the topics, tasks, and completion criteria for the
individual topics. The system tracks the users progress through
the topics in the course. This approach is illustrated by the presentation
of an organizer for an online course in Managerial Decision Making.
Future work will proceed along two paths, extending the basic capabilities of
the editor/runtime system and integrating the system with other on-line
learning environments. As an example of integrating this system with other
on-line instructional systems, the Advanced Distributed Learning (ADL)
initiative  by the White House Office of Science and Technology and
the DoD seeks to create reusable on-line courseware objects and a standard
method of cataloguing, searching and presenting them. The organizer could
easily be adapted as an editor to generate XML course descriptions (CSF
records) in the standardized format prescribed by the SCORM, and to serve
as a front end for the learning systems themselves.
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