Since the very beginning of the research on Adaptive Hypermedia Systems (AHS), different systems have been developed for different domains and application areas. Besides some general features, which are expected to be present in any software system, AHSs have their own extra features that make them different from non-adaptive systems. Through a careful study of a large number of adaptive hypermedia systems, a hierarchy of primary features based on which one can evaluate different adaptive web systems are proposed. An evaluation weighting scheme is also proposed for the given features. A comparative analysis is carried out for 4 major adaptive hypermedia systems (AHA!, InterBook, STEA and SeAN). The results of our detailed evaluation put AHA! at the top followed by SETA, SeAN and InterBook, respectively. 1

A framework has been developed as a basis for design and implementation of adaptive Web systems. This framework and the respective architecture support the idea of high-level synthesis and facilitate different types of adaptation. In this paper, we describe main components in the framework, and introduce an example application from e-News domain, a personalized electronic news system (PENS). PENS is implemented as the proof of concept and to demonstrate how Web pages are synthesized with different attributes from the same description, and to show adaptation based on users ’ behavior and client-side characteristics.

Abstract. An adaptive Web system adapts the Web pages to its users, based on the current state of the system. There are two approaches to this page adaptation: either the pages exist statically or they are generated dynamically. In the first approach, the system may add, remove, or change the fragments inside the pages to adapt it. In this case, since the pages are predesigned, there are limitations to the changes that can be applied. On the contrary, when the pages are generated dynamically (the second approach), all the features and attributes of the pages may be customized based on the current state of the system. In this paper, we formalize dynamic generation of Web pages and refer to it as Web page synthesis. An architecture for an adaptation server, which uses a synthesis engine to generate Web pages, is proposed. 1