Lisa Seeman, UB Access
The Semantic Web may vastly improve the ability of the web to address the needs of people in different scenarios , including people with disabilities, without putting undue burden on web authors. RDF, annotation technology and knowledge based representation of web content , create a solution to address dilemmas as access , including access for people with learning disabilities and aid improvements in future accessibility policies.
It is worth noting that knowledge based accessibility techniques ubiquitously promote other aims of Web Design including device independence, internalization and localization. These advantages will serve to encourage Web authors to incorporate more accessibility into their sites, and to create a more accessible Web. For example, Semantic web statements about page structure can be interpreted to create enhanced navigation views that enables non-sighted users to orientate themselves on a page, scan the page, and access the sections that interest them most can also be used to enhance navigation for mobile devices. Statements about associations of presentation can be interpreted across user medium to enhance the user experience.
Currently, sites intended to be user-friendly to several cognitively disabled communities rely on the use of simple language and illustrations and a clear page layout. Unfortunately all these techniques usually are associated with changing the look and feel of the page.
Not surprisingly many otherwise accessible sites are reluctant to seriously consider access techniques for the learning disabled. A classic accessibility dilemma is when accessibility involves changes to the look and feel of the page.
However annotations, such as RDF (Resource Description Framework) annotations, allow an author to make statements about the content, sections of the content or even specific words
Another important use of semantic annotations is to describe the role of sections of content. Example of role information include: Main menu, sub menu, legal footer, sitemap link, contact us link etc.
The roles themselves are defined in RDF so that the relationships between roles are defined. New roles and roles tailored for specific web communities can be defined from base roles.
Understanding the role of sections of content allow them to be presented on different devises and for different users predictable and simply. Access keys can be assigned to roles across the web. It can also help facilitate information hiding, and allow the user the amount of screen content that is most appropriate for there scenario.
An implementation by UB Access is SWAP (the Semantic Web Accessibility Platform), a semantic web, knowledge based approach to accessibility. SWAP creates alternative renderings of sites, or SWAPviews, which enable people with diverse special needs to smoothly and easily access the content. SWAP uses annotations, which reflect extra accessibility-related information about each page content , concepts, and relationships .
Using Semantic Web as outlined is one example of the potential direction for the evolution of accessibility. This is in the case where full accessibility support would be implemented through the use of the semantic web. Semantic Web accessibility usage could solve accessibility problems in the following situations:
Further, XML schema can be annotated to increase accessibility usage, which could have an effect of an immeasurable number of documents based on that schema.
Multiple alternatives / conditional content in different medias can be provided. For instance, an auditory rendering of a visual aid might be more appropriate in some contexts than text.
The ultimate aims being to broaden the scope of web accessibility, to offer better access to more people and to integrate accessibility requirements, the semantic web, and accessibility interfaces to the net.
[WCAG10] "Web Content Accessibility Guidelines 1.0", W. Chisholm, G. Vanderheiden, and I. Jacobs, eds., 5 May 1999. This WCAG 1.0 Recommendation ishttp://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505/.
[WCAG20] "Web Content Accessibility Guidelines 2.0", Ben Caldwell, W. Chisholm, Jason White and G. Vanderheiden, eds., 28 August 2002
[RDF] "Resource Description Framework (RDF) Model and Syntax", O. Lassila and R. Swick, eds., 22 February 1999. W3C Recommendation.
[RDF Schemas] "Resource Description Framework (RDF) Schema Specification 1.0", D. Brickley and R.V. Guha, eds., 27 March 2000. W3C Candidate Recommendation.
[XML] Extensible Markup Language, Franois Yergeau, Tim Bray, Jean Paoli, C. M. Sperberg-McQueen, Eve Maler http://www.w3.org/TR/2004/REC-xml-20040204/
[XAG] XML Accessibility Guidelines? , Daniel Dardailler, Sean B. Palmer, Charles McCathieNevile http://www.w3.org/TR/xag