The CISNA model of accessible adaptive hypermedia

With the growth of script-intensive web pages, particularly those using AJAX technology, the adaptation of Web content to match the needs and capabilities of individual users has become increasingly problematic. New versions of well-known websites, including for example Google Suggest, which is an AJAX driven variant of their standard search page, are now largely opaque to screen reading technology such as Jaws. Taken together with the trend to surf the Web on small hand-held devices, which causes its own accessibility problems, a new approach to expressing heavily scripted content is needed. This research returns to first principals, and considers the underlying Dexter Model of Hypertext, and how that may be placed within a broader model of document content that is amenable to adaptation of content to user needs either through configuration, or through dynamic self-adaptation. The model proposed considers a document in terms of five individual abstractions: content, inventory, semantics, navigation, and adaptation. A simple (fully working) example, taken from a small fragment of Google Maps, is presented to demonstrate how such a model may operate in practice, adapting between two different user profiles on demand.