ABEL-GUI: AN AGENT-BASED GRAPHICAL USER INTERFACE
FOR E-LEARNING
Steffen Kernchen, Fritz Zbrog and Reiner R. Dumke
Department of Computer Science, Otto-von-Guericke-University of Magdeburg, Magdeburg, Germany
Keywords:
e-Learning, Agent Technology, Graphical User Interface.
Abstract:
In this paper we present an agent-based graphical user interface (GUI) for the domain of e-Learning: the
ABEL-GUI. It is developed following a structured approach for the analysis, specification and design of agent-
based graphical user interfaces. Therefore a logical goal/task hierarchy is designed and depicted by a society
of agents. By this an implicit partition of the GUI takes shape and gets connected with the particular agents.
The result takes benefits from the cooperation idea behind agent technology and focuses on specialization,
personalization and interaction support.
1 INTRODUCTION
We think creating interfaces based on agent techno-
logy does not only follow the new paradigm of agent-
based software development but leads to several ad-
vantages, too. O’Malley et al. list several guide-
lines whether an agent-oriented approach is useful
(O’Malley and DeLoach, 2002). According to them
agent-based graphical user interfaces can be neces-
sary, because:
GUI’s may include complex/diverse types of in-
teraction between components as well as to ex-
tern distributed heterogeneous resources. This
flexibility of protocols can be easily supported by
agent technology.
Negotiation, cooperation and competition may
occur among different entities.
Some aspects of a GUI can have autonomous
characteristics.
A modification or expansion of the system can be
anticipated. By using agents this flexibility is ex-
tended to modification or expansion during run-
time of the system.
By choosing an agent-based approach additional
aspects of flexibility can be applied for the domain
of e-Learning. An increased support of adaptation
for example leads to an improved adaptation to the
user’s needs. By choosing the developmentmethodol-
ogy presented in chapter 4 in combination with agent
technology level-based as well as agent-based person-
alization of the functionality and the appearance of
the GUI is possible. Basis of the adaptation are de-
mands, properties, preferences, skills or interactions
of the user that may occur or are explicitly modelled
within a user model.
By means of agent technology, a framework de-
velopment becomes possible. It can provide basic
functions to fulfil minimal requirements. Additional,
specialized agents can be added during runtime to ex-
tend the GUI. Thereby lightweight software provision
and functional adaptation are distinguishing features
of the system.
But why so much flexibility for e-Learning? Lear-
ning is one of the most important aspects of our cul-
ture. Its effective implementation and support is es-
sential for human beings in all phases of their life.
Life-long learning is the corresponding slogan. There
are many changes in that long period of time. That
refers to internal human being aspects as well as to
external environmental ones. Human lifelong devel-
opment requires highly flexible mechanisms for the
adaptation of supporting systems. That applies to
learning in a particular manner. External reasons are
new scientific knowledge about didactics, psychol-
491
Kernchen S., Zbrog F. and R. Dumke R. (2007).
ABEL-GUI: AN AGENT-BASED GRAPHICAL USER INTERFACE FOR E-LEARNING.
In Proceedings of the Third International Conference on Web Information Systems and Technologies - Society, e-Business and e-Government /
e-Learning, pages 491-494
DOI: 10.5220/0001271504910494
Copyright
c
SciTePress
ogy, interface design and new information about the
topic to be learned. Versatile problems require adap-
tive and extendable solutions.
Following an agent-oriented methodology for de-
signing graphical user interfaces we developed a
framework of a front-end for a highly adaptive e-
Learning system.
This paper is organized as follows. In section 2 we
present basic key aspects that need to be considered in
the context of our approach. The important factor of
usability as well as the plug-in technology and the ad-
ditional value contained in our approach are sketched
out. The used methodology for the development of
agent-based graphical user interfaces is presented in
section 3. Key elements and novel features of the de-
veloped ABEL-GUI are part of section 4. Section 5
closes this paper with conclusions and future work.
2 FUNDAMENTALS
Following Shneiderman and Plaisant user interface
design should be driven by user tasks and interface
mechanisms (Shneiderman and Plaisant, 2005). The
identified tasks must be real, complete and represen-
tative and the design that is developed following this
task-centred approach must be validated to be appro-
priate. The other key element is the communication
between user and system. The interface mechanisms
must provide appropriate support for the user to solve
his actual task.
There are three paradigms of user interface de-
sign described in (Tsou and Buttonfield, 1998). Tra-
ditional user interfaces operate within a centralized
environment. They are not platform- and application
independent. Client/Server user interfaces are clients
remote connected with one server where data and pro-
gram are located. They are usually platform indepen-
dent like global user interfaces, which are not limited
to connect to only one server. These interfaces can
access multiple heterogeneous systems.
Traditional User Interface Client/Server User Interface Global User Interface
Interface
Programs
Data
Server
Client Interfaces
Client with Global
Interfaces
Distributed Servers
Figure 1: Three paradigms of user interface design (Tsou
and Buttonfield, 1998).
Plug-in technology is an approach that targets the
concept of mobile codes. Plug-ins are supplement
software modules which are integrated in other soft-
ware. They are only working in order with the appli-
cation they are written for. Technologically they can
be implemented in various ways: .NET, DCOM and
Enterprise Java Beans to name a few.
Both approaches differ in the flexibility of usage
and adaptation. Autonomous, pro-active and cooper-
ative characteristics of agent technology are aspects
that are not part of plug-ins, but provide essential ad-
vantages for the usage in context of e-Learning sys-
tems.
3 DEVELOPING AGENT-BASED
GRAPHICAL USER
INTERFACES
For developing agent-based graphical user interfaces
an iterative goal-directed methodology including de-
sign patterns and creative techniques is presented
here. As visualized in figure 2 there are several de-
sign stages.
Identification of goals
Hierarchical subdivision of goals
- depending on complexity
Identification of functional requirements
- definition of additional properties
Hierarchical subdivision of functions
- depending on complexity
Derivation of functional dependencies
- to other agents
- to extern components
- definition of additional properties
Determination of required and optional data
Goals
Tasks
Inter-
actions
Agent-based meaning GUI-based meaning
Presentation
containers
Visual and
functional
elements
Functional
dependences
Subdivision of functional dependencies
- depending on complexity
Post refinement activities
- mapping of funtional objects to agents
- detailed description of egdes and nodes
Figure 2: Stages of developing agent-based GUIs.
At the first stage the goals that should be solved
are defined and refined. The starting point is the given
problem in a special application domain. The goals
and sub-goals have general character and form a tree.
No special functions will be defined yet.
WEBIST 2007 - International Conference on Web Information Systems and Technologies
492
The special functionalities that are needed to reach
the defined goals are identified at the second stage. If
a function is too complex for an easy implementation
its subdivision in smaller nodes is recommended. The
complexity does not only refer to the functionality but
also to the amount of dependencies to other nodes or
external components.
A tree-shaped structure based on the subdivision
of goals and tasks is defined so far. Now this structure
is extended by the definition of additional internal and
external connections. Next to the connections of the
specified goal and task hierarchy - the edges of the
tree - more internal functional dependenciesmay exist
and need to be specified: a graph structure develops.
Up to this point the general structure of the multi-
agent system and the graphical user interface is mod-
elled. The next steps are the mapping of functional
objects, respectively sets of those objects, to agents
and the detailed description of edges and nodes. Com-
plexity measures like the number of sub-functional
objects or the number of edges can indicate an appro-
priate mapping. Sometimes aspects of the later im-
plementation need to be taken into account, too. By
recombining functionalities all sub-functional objects
as well as all internal and external connections are
compressed into one agent without disregarding the
detailed functional design.
4 AGENT-BASED GUI FOR
E-LEARNING
As already stated out flexibility, adaptation and per-
sonalization are key features of a GUI for e-Learning.
Using the previously described methodology we de-
veloped a graphical user interface based on agent
technology. By turning into account its heteroge-
neous and autonomous characteristics the intended
goals can be achieved.
ManagementLearning
RLO
User model
E-learning platform
Performance
observation
RLO database
User model server
Personal space Interaction
Communication
server
Figure 3: Core components of the ABEL-GUI and selected
transitive connections to external distributed elements.
The framework benefits from the autonomy char-
acteristic of agent technology in terms of improved
modularity, adaptivity and flexibility. Proactivity and
reactivity may directly result in adaptive changes
of the component presentation. An example is the
preference-based sortation of collaboratives in a chat
list.
In this section we introduce main concepts of the
architecture of the developed system from a student’s
point of view. Other roles are tutor, author and ad-
ministrator and lead to a distinct usage of existing el-
ements as well as to completely new features.
4.1 Learning Components
The first and obviously most important parts of the
GUI to be developed are the learning components.
That refers to all goals and functions that are directly
coupled with the learning tasks.
Following the already described methodology we
identified four direct sub-goals and one direct func-
tionality, namely the course, course structure, domain
visualization, support and actual announcements.
Course
structure
Course
Domain
visualization
Support
Actual
announcements
RLO
User model
E-learning platform
Course
management
Performance
observation
RLO database User model server
Domain
ontology
Motivation
HelpAvatar
RSS-Feed
Hierarchy Node
Figure 4: Graph presenting learning components, sub-
components and functional edges.
4.2 Management Components
The adaptive functionality of this system is based on
technical as well as organizational management. That
refers to the management of agents, courses, user
model and to logging mechanisms.
Course
management
Agent
management
User model
E-learning platform
User model server
User model
management
System
management
Logging
Agent
catalogue
Visualization
Student
management
Student
observation
Student
tests
Figure 5: Graph presenting management components, cho-
sen sub-components and functional edges.
4.3 Personal Components
Personal parts that might be implemented in an e-
Learning GUI are e.g. a personal homepage, a course
scheduler,personal space for storing of files and infor-
mation, individualized search mechanisms and a kind
ABEL-GUI: AN AGENT-BASED GRAPHICAL USER INTERFACE FOR E-LEARNING
493
Course
s
Personal
homepage
User model
E-learning platform
User model server
Personal space
Individual
search
mechanisms
Diary
User server
Figure 6: Graph presenting personal components, sub-
components and functional edges.
of diary. A user server might be a technological base
for these elements.
4.4 Interaction Components
Human interaction is essential for learning and
learning-related motivation (e.g.: (Walther, 1992),
(Dimitrova et al., 2003)). Our approach offers vari-
ous core synchronous and asynchronous communica-
tion supporting elements and the easy usage, update
and extension of this set. Examples are a wiki, chats,
forums, user search component, etc.
All interaction components imply functional con-
nections to the user model, the user server and the
communication server. Preferences and logfiles need
to be stored for every communication tool for person-
alization and adaptation.
L
users
Wiki
User
model
E-learning platform
User model server
ForumChat
User
search
Communication server
Text Video Audio
Figure 7: Graph presenting interaction components, chosen
sub-components and functional edges.
4.5 Implementation Remarks
This GUI is intended to be implemented as a frame-
work. That is an important aspect for the provision of
the flexibility, the necessity and advantages of which
was proven in the introduction. Therefore minimal
required elements as well as necessary infrastructural
aspects must be defined.
At this point we argue that the core elements
shown in figure 4, their direct sub-elements and all
elements, that are directly or transitive connected by
required edges, are non-optional parts of the frame-
work. This is visualised in the particular figures of
the other subsections of this section.
Infrastructural aspects that must be respected are
the identification of agents, docking mechanisms,
interaction interfaces, the communication itself and
warranty of role-based access and modification is-
sues.
Interaction is one of the most important features of
agent technology. Most of their advantages are based
on communication. In the context of interfaces exter-
nal and internal communication needs to be optimized
to guarantee the flow of usage. Those are contrary
goals that must be carefully balanced and that directly
refer to the implementation technology.
Performing post-refinement activities is a stage of
the used methodology that is between refinement of
goals/functionalities and the implementation. It pools
sub-functions belonging together into one agent.
5 CONCLUSIONS AND FURTHER
WORK
In this paper we presented main concepts of the
ABEL-GUI, a graphical user interface for the do-
main of e-Learning, which was developed following
a graph-based approach for developing agent-based
GUI’s. High flexibility, organized interaction mech-
anisms as well as adaptation support are key benefits
of this technique. To examine the usefulness of our
approach we modelled the presented agent-based in-
terface for the e-Learning domain as a framework. An
integral part of our future research is its implemen-
tation using existing web technologies by extending
them with agent characteristics.
REFERENCES
Dimitrova, M., Sadler, C., Hatzipanagos, S., and Murphy,
A. (2003). Addressing learner diversity by promoting
flexibility in e-learning environments. In Proceedings
of the 14th International Workshop on Database and
Expert Systems Applications (DEXA03).
O’Malley, S. A. and DeLoach, S. A. (2002). Determing
When to Use an Agent-Oriented Software Engineering
Paradigm, pages 188–205. Springer.
Shneiderman, B. and Plaisant, C. (2005). Designing
the User Interface Strategies for Effective Human-
Computer Interaction. Pearson Education, 4th edition.
Tsou, M.-H. and Buttonfield, B. (1998). An Agent-Based,
Global User Interface for Distributed Geographic In-
formation Services. In Proceedings of the 7th Inter-
national Symposium on Spatial Data Handling, pages
602–612.
Walther, J. B. (1992). Interpersonal effects in computer-
mediated interaction: A relational perspective. Com-
munication Research, pages 52–90.
WEBIST 2007 - International Conference on Web Information Systems and Technologies
494