Collaborative Environments: Accessibility and Usability for Users with Special Needs - Community-Built Databases: Research and Development - page 327

constraints could be counterproductive since it does not necessarily entail an
improvement in the overall browsing experience for people with disabilities.
Passing the tests of automatic tools for checking accessibility does not guarantee
that the Web site as well will be usable.
Moreover, new challenges have emerged from the introduction of Web 2.0
facilities that are not covered by WCAG 1.0/ATAG 1.0. Collaborative environ-
ments in which the content is permanently incremented with successive refinements
are completely different from Web 1.0 environments where Web sites owners are
the only ones responsible for the published content. These challenges are more user
oriented than technical and require that developers consider usability aspects within
the technical guidelines.
To address these issues, in December 2008 a new version of the W3C guidelines
was made available with the publication of the W3C Recommendation of WCAG
2.0 [ 37 ]. For what concerns the guidelines for authoring tools, a Working draft
(ATAG 2.0 [ 38 ]) has been published in October 2009.
The approach of WCAG 2.0 is different from the one adopted in WCAG 1.0. The
proposal is neither HTML specific nor CSS specific and the intended audience is
wider including, on the one hand, the target user, (i.e., people with different forms of
disability) and, on the other hand, Web content producers such as Web designers and
developers, but also teachers and students. For each proposed guideline, success
criteria are provided and (like inWCAG 1.0) three levels of conformance are defined:
A (lowest), AA (middle), and AAA (highest). For each guideline and success criteria,
sufficient and advisory techniques for meeting success criteria have been defined.
The guidelines are classified under four POUR principles [ 37 ]:
1. Perceivable, i.e., users must be able to sense the Web content which cannot be
invisible to all of their senses.
2. Operable, i.e., users must be able to use the interface that cannot require
interaction that they are not able to perform.
3. Understandable, i.e., users must be able to understand the information, as well as
the operation of the user interface.
4. Robust, i.e., users must be able to access the content as technologies advance.
The WCAG 2.0 guidelines are shown in Table 13.4 , together with indications of
the form of disability they might address; their numbering suggests the principle with
which they are associated. Further details on WCAG 2.0 can be found online [ 37 ].
ATAG 2.0 splits the guidelines for authoring tools into two parts. Part A,
promoting their accessibility, and Part B, supporting the automatic production of
accessible Web content for end users. Guideline 7 of ATAG 1.0 has been
enhanced with a dedicated section for the development of accessible authoring
tools including HTML editors, software for converting to Web content technol-
ogies, collaborative software for updating portions of Web pages (e.g., blogs,
wikis, online forums), content management systems, and many others. It is
particularly important to guarantee access to user-generated content environments
to people with disabilities. Further details of ATAG 2.0 can be found in the
official online documentation [ 38 ].