Design issues for general-purpose adaptive hypermedia systems

ABSTRACT

A hypermedia application offers its users much freedom to navigate through a large hyperspace. For authors finding a good compromise between offering navigational freedom and offering guidance is difficult, especially in applications that target a broad audience. Adaptive hypermedia (AH) offers (automatically generated) personalized content and navigation support, so the choice between freedom and guidance can be made on an individual basis. Many adaptive hypermedia systems (AHS) are tightly integrated with one specific application. In this paper we study design issues for general-purpose adaptive hypermedia systems, built according to an application-independent architecture. We use the Dexter-based AHAM reference model for adaptive hypermedia [7] to describe the functionality of such systems at the conceptual level. We concentrate on the architecture and behavior of a general-purpose adaptive engine. Such an engine performs adaptation and updates the user model according to a set of adaptation rules specified in an adaptation model. In our study of the behavior of such a system we concentrate on the issues of termination and confluence, which are important to detect potential problems in an adaptive hypermedia application. We draw parallels with static rule analysis in active database systems [1,2]. By using common properties of AIIS we are able to obtain more precise (less conservative) results for AHS than for active databases in general, especially for the problem of termination.

REFERENCES

• 1: Alexander Aiken , Joseph M. Hellerstein , Jennifer Widom, Static analysis techniques for predicting the behavior of active database rules, ACM Transactions on Database Systems (TODS), v.20 n.1, p.3-41, March 1995 [doi>10.1145/202106.202107]
• 2: Elena Baralis , Jennifer Widom, An algebraic approach to static analysis of active database rules, ACM Transactions on Database Systems (TODS), v.25 n.3, p.269-332, Sept. 2000 [doi>10.1145/363951.363954]
• 3: Brusilovsky, P. Methods and Techniques of Adaptive Hypermedia. User Modeling and User-Adapted Interaction, 6, pp. 87-129, 1996. (Reprinted in Adaptive Hypertext and Hypermedia, Kluwer Academic Publishers, pp. 1-43, 1998.)
• 4: Baralis, E., Ceri, S., Paraboschi, S. ARACHNE: A tool for the analysis of active rules. Proceedings of the Second International Conference on Applications of Databases, pp. 68-81, (Santa Clara, December 1995).
• 5: Stefano Ceri , Jennifer Widom, Deriving production rules for constraint maintenance, Proceedings of the sixteenth international conference on Very large databases, p.566-577, September 1990, Brisbane, Australia
• 6: De Bra, P., Calvi, L. AHA! An open Adaptive Hypermedia Architecture. The New Review of Hypermedia and Multimedia, pp. 115-139, 1998.
• 7: Paul De Bra , Geert-Jan Houben , Hongjing Wu, AHAM: a Dexter-based reference model for adaptive hypermedia, Proceedings of the tenth ACM Conference on Hypertext and hypermedia : returning to our diverse roots: returning to our diverse roots, p.147-156, February 21-25, 1999, Darmstadt, Germany [doi>10.1145/294469.294508]
• 8: Halasz, F., Schwartz, M. The Dexter Reference Model. Proceedings of the NIST Hypertext Standardization Workshop, pp. 95-133, 1990.
• 9: Frank Halasz , Mayer Schwartz, The Dexter hypertext reference model, Communications of the ACM, v.37 n.2, p.30-39, Feb. 1994 [doi>10.1145/175235.175237]
• 10: Hothi, J., Hall, W. An Evaluation of Adapted Hypermedia Techniques Using Static User Modeling. Proceedings of the Second Workshop on Adaptive Hypertext and Hypermedia, pp. 45-50, 1998.
• 11: Norman W. Paton , Oscar Díaz, Active database systems, ACM Computing Surveys (CSUR), v.31 n.1, p.63-103, March 1999 [doi>10.1145/311531.311623]
• 12: Hongjing Wu , Paul De Bra , A. T. M. Aerts , Geert-Jan Houben, Adaptation Control in Adaptive Hypermedia Systems, Proceedings of the International Conference on Adaptive Hypermedia and Adaptive Web-Based Systems, p.250-259, August 28-30, 2000

INDEX TERMS

Primary Classification:
  H. Information Systems
  H.5 INFORMATION INTERFACES AND PRESENTATION (I.7)
      H.5.4 Hypertext/Hypermedia
          Subjects: Navigation

Additional Classification:
  H. Information Systems
  H.5 INFORMATION INTERFACES AND PRESENTATION (I.7)
      H.5.4 Hypertext/Hypermedia
          Subjects: User issues

General Terms:
Design

Keywords:
active databases, adaptation rules, adaptive hypermedia, confluence, termination, user modeling