© FORMATEX 2006
Accessibility and Model-Based Web Application Development
for eLearning-Environments
Sabina Jeschke
1
, and Helmut Vieritz
1*
1
Berlin University of Technology, Department of Mathematics and Natural Sciences, Straße des 17. Juni
136, D-10623 Berlin, Germany
Especially eLearning and eScience technologies offer a wide range of possibilities for pedagogical
concepts supporting individual demands and interests. The two deciding factors are given by its
interaction capability and the ability to adapt to the user, both practically unachievable using traditional
media. These two features are the key to extend the methodology of teaching scenarios as well as the
support of individual learning strategies - the integration of new media into the academic education thus
possesses the potential to assist in transcending the disadvantages in the education of disabled people.
Based on semantic content encoding and model-based development, a broad range of accessibility
features can be supported. Within the BeLearning-Project at the Berlin University of Technology, these
issues are investigated.
Keywords accessibility; model-based Web application development; conceptual modeling; user-centered
design
1. Introduction
Learning and eScience platforms are characterized by non-linear information structures and intensive use
of graphical and interactive components. Together with the dynamic generation of content are these the
properties, which lead to new presentation approaches and new forms of learning environments.
Unfortunately, the resulting Web applications are often not accessible for disabled persons. On the other
hand, computer-based technology allow a complete separation between content and presentation.
Therefore, new media possess the potential to adapt the presentation to individual users in principle. To
build accessible Web applications, one has to respect the needs from the beginning of the design process.
Based on recent proposals for a model-based Web application development, we discuss the essential
modeling requirements to ensure enhanced accessibility in eLearning environments for education. A
number of guidelines (designed and published by the World Wide Web Consortium (W3C), the
European Commission, national governments and others) have been passed during the last years to
address the issue of accessibility. The majority of the suggested rules focus on easy access to (more or
less static, less interactive) information portals. Often, the paradigm of a universal design for all people is
assumed. However, the existing concepts do not address the implementation of highly multimedia-based
interactive learning and teaching contents for disabled persons, nor are they well-suited to this task.
Advanced eLearning platforms are capable to adapt the presentation to the user and they can provide him
with additional information about multimedia content, navigation and presentation suited to his own
needs. Therefore, the universal design approach can be replaced by a user-centered or target-group-
specific design which is based on two main paradigm:
Semantic encoding: The flexibility of the separation of content and representation requires extensive
semantic encoding of the complete content: supporting the underlying semantic technologies is vital to
the realization of a broad accessibility of highly interactive virtual knowledge spaces and incorporating
intelligent tools for the development and administration of content. Here, it is important to mention that
semantic encoding may not be restricted to the content elements themselves, but has to be extended to all
aspects which are highly content-related as, for example, navigation mechanisms. Semantic encoding
* *
Corresponding author: e-mail: vieritz@math.tu-berlin.de, Phone: +49 30 31429941
Current Developments in Technology-Assisted Education (2006) 1161