Sadie: Structural semantics for accessibility and device independence

Visually impaired users are hindered in their efforts to access the largest repository of electronic information in the world, namely, the World Wide Web (web). A visually impaired user’s informa-tion and presentation requirements are different from a sighted user’s. These requirements can become problems in that the web is visually centric with regard to presentation and information order/layout. Finding semantic information already encoded directly into documents can help to alleviate these problems. Our approach can be loosely described as follows. For a particular cas-cading stylesheet (CSS), we provide an extension to an upper-level ontology which represents the interface between web documents and the programmatic transformation mechanism. This exten-sion gives the particular characteristics of the elements appearing in that specific CSS. We can consider this extension to be an annotation of the CSS elements implicitly encoded into the web document. This means that one ontology can be used to accuratly transform every web document that references the CSS used to generate that ontology. Simply one ontology accuratly transforms an entire site using a generalized programmatic machinery able to cope with all sites using CSS. Here we describe our method, implementation, and technical evaluation