Adaptive educational hypermedia: From ideas to real systems

Adaptive hypermedia is a new area of research at the crossroads of hypermedia, adaptive systems and intelligent tutoring systems. The goal of this paper is to present the ideas of adaptive hypermedia to an educational hypermedia-oriented audience and to show some ways of implementing adaptive hypermedia systems. This paper considers two kinds of hypermedia adaptation : adaptive presentation and adaptive navigation support . We provide a brief overview of existing works on each of these two kinds of adaptation and describe in more detail two existing tutoring systems which contain adaptive hypermedia components. These systems demonstrate some ways to implement adaptive presentation and adaptive navigation support in an educational context . The use of adaptive hypermedia systems (AHS) is one of the ways of increasing the functionality of hypermedia . AHS build a model of the goals, preferences and knowledge of the individual user and use this throughout the interaction for adaptation to the needs of that user. Adaptive hypermedia can be useful in any situation when the system is expected to be used by people with different goals and knowledge, where the hyperspace is reasonably big, or where the system can successfully guide the user in his or her work. Education is one of the most promising areas for adaptive hypermedia. Hypermedia is used in educational systems for providing student-driven exploration of educational material . Adaptive hypermedia can be applied here for all the above reasons: to adapt the presented information to the current knowledge level of the student [Brusilovsky, Pesin & Zyryanov, 1993] [Beaumont, 1994], to provide navigation support on various levels [de La Passardiere & Dufresne, 1992][Brusilovsky, Pesin & Zyryanov, 1993] and to guide the student in the learning process [Brusilovsky, Pesin & Zyryanov, 1993][Kushniruk &Wang, 1994]. The goal of this paper is to present the ideas of adaptive hypermedia to a general hypermedia-oriented audience and to'show some ways to implement AHS. This paper considers two kinds of hypermedia adaptation : adaptive presentation and adaptive navigation support. We provide a brief overview of existing works on each of these two kinds of adaptation and describe in detail two existing tutoring systems which contain adaptive hypermedia components . These systems demonstrate some ways to implement adaptive presentation and adaptive navigation support in an educational context. Adaptive presentation is the most popular and the most studied method of hypermedia adaptation . Thework on adaptive hypermedia presentation was influenced by work on adaptive user interfaces, namely, the work of C. Paris on adaptive explanations [Paris, 1989] . With adaptive presentation the content of a hypermedia page is generated or assembled from pieces according to the user's class and knowledge state . Generally, qualified users receive more detailed and deep information, while novices receive more additional explanation [Beaumont, 1994][Brusilovsky, 1992] [Boyle & Encarnacion , 1994] [Fischer et al, 1990] Two popular application areas for adaptive presentation are adaptive hypermedia-based help in knowledge-based systems [Fischer et al, 1990][De 11 1 Current address: Department of Cognitive Psychology, University of Trier, Germany