Collaborative Environments: Accessibility and Usability for Users with Special Needs - Community-Built Databases: Research and Development - page 320

materials. To describe this double role of the users who are no longer only simple
consumers but also producers of knowledge, the term “produser” was coined [ 4 ].
The main idea of e-learning technologies is to offer teachers and students the
control over content, learning sequence, pace of learning, time, and often media,
allowing them to tailor their experiences to meet their personal learning objectives.
Unfortunately, most e-learning systems omit clear and measurable objectives and
strategies for supporting collaborative processes and the evolution of the teachers'
and the students' communities in a community of e-learning content providers.
Starting from the user requirements, e-learning systems should guarantee the
fruition of content at multiple levels, from access to generation, to large communities
of users, each of them characterized by different abilities, skills, and requirements,
acting in a variety of use contexts and adopting different technologies [ 31 ]. We think
this is particularly true in the educational context where the access to the software
and learning material should be guaranteed to all learners, thus facilitating the
inclusion of those with different abilities. We remark that users affected by disabil-
ities like blindness and low vision, deafness and hearing loss, learning disabilities,
cognitive limitations, motor difficulties, and speech difficulties are around 50 million
in the European Union (10% of its population) [ 7 ]. Moreover, this need of acce-
ssibility is of great interest to international consortia, like the WWW Consortium
(W3C), and national governments that have issued recommendations and laws for
the formulation of accessibility guidelines in order to develop software tools useful
for citizens with disabilities.
Besides accessibility issues, e-learning applications have to face more general
problems related to usability. Usability guidelines, initially proposed for traditional
interactive systems [ 6 , 10 ], have been currently enhanced to take into account the
social creation of knowledge [ 12 , 30 , 33 ] and the users' need to be more aware
about the actions of the rest of the users in collaborative e-learning classes.
For these reasons, the purpose of this chapter is to define a model for supporting
the design and development of collaborative e-learning systems accessible and
usable by teachers and by all students during their activities of fruition or genera-
tion of educational materials. The model, which is inspired by already existing
usability models but places a strong emphasis on accessibility and collaboration,
has been conceived during the development of VisualPedia [ 2 ], an accessible wiki-
based e-learning system that will also be introduced.
The chapter starts with a presentation of assistive tools that can be used for
interacting with computer systems and that should be considered when developing
collaborative environments. Indeed, users with special needs can exploit one (or
more) of them to interact with the collaborative environment. Then, in Sect. 13.3
an overview is given of the current usability models for the design and the
development of interactive environments, and the W3C accessibility guidelines
are briefly described. Once the usability models and the accessibility guidelines have
been described, we present the experience we gained in designing and developing
VisualPedia, an accessible and collaborative e-learning platform. Special emphasis
will be given to the usability and collaborative characteristics of this system and to the
problems that emerged during our usability analysis. Starting from the QUIM model