XAHM: An XML-Based Adaptive Hypermedia Model and Its Implementation

This paper presents an XML-based Adaptive Hypermedia Model (XAHM) and its modular architecture, for modelling and supporting Adaptive Hypermedia Systems, i.e. hypertext-based multimedia systems that allow user-driven access to information and content personalization. We propose a graph-based layered model for the description of the logical structure of the hypermedia, and XML-based models for the description of i) metadata about basic information fragments and ii) "neutral" pages to be adapted. Furthermore, we describe a modular architecture, which allows the design of the hypermedia and its run-time support. We introduce a multidimensional approach to model different aspects of the adaptation process, which is based on three different "adaptivity dimensions": user’s behaviour (preferences and browsing activity), technology (network and user’s terminal) and external environment (time, location, language, socio-political issues, etc.). An Adaptive Hypermedia is modelled with respect to such dimensions, and a view over it corresponds to each potential position of the user in the "adaptation space"; the model supports the adaptation of both contents and link structure of the hypermedia.