AHA! Adding adaptive behavior to websites

Most websites offer information that appeals to a wide audience. However, a single presentation may not be suitable for that wide range of people wishing to visit the website. AHA! is a server extension that makes it possible to adapt the content shown on webpages, and the links that appear on these pages, to each individual user. An AHA! application consists of a concept-structure and a set of XHTML pages. The concept-structure (which can be defined using a high-level graphical tool or a low-level editor) consists of concepts, attributes and condition-action rules that determine user model updates and conditions for object inclusion. The XHTML pages use the ''object'' tag to indicate where conditionally included objects should be placed. The condition-action rules determine which information is included, if any. The rules also determine the ''suitability'' of pages for a given user. Links to pages are shown in a different way depending on this suitability. Many adaptive systems exist today. They target a specific application area, like on-line textbooks, information kiosks, corporate information systems, etc. AHA! provides a general-purpose adaptive system. Current research and development efforts concentrate on improving the authoring support, e.g. by automatically detecting potential loops in the condition-action rules