CSA402

Lecture 11

Introduction to
Adaptive Hypertext Systems

Why Adaptive Hypertext?

Definition

"... all hypertext and hypermedia systems which reflect some features of the user in the user model and apply this model to adapt various visible aspects of the system to the user."
Brusilovsky, P. 1998. 'Methods and Techniques of Adaptive Hypermedia', in Brusilovsky, P., Kobsa, A., and Vassileva, J. (eds) Adaptive Hypertext and Hypermedia. Netherlands: Kluwer Academic Publishers, 1-43.

Scenarios

• A system that caters for users with different levels of expertise, both in system use, and with the content (e.g., domain experts/interface novices, domain novices/interface experts, domain novices/interface novices, domain experts/interface experts)

• A tutoring system which enables students to progress at their own speed/level of competence (e.g., Intelligent Tutoring Systems, which are different from Computer-based Training Systems)

• A system which supports users with different level of physical ability (e.g., people with different physical disabilities)

• A organisational system in which data is shared by people in different departments (e.g., th same information could be used differently by people in sales/marketing/finance)

• A system which takes into account different methods of access (e.g., high-speed LAN access, low-speed home access, mobile access)

Four generic environments in which adaptivity can be beneficial

• systems used by users with different requirements

• systems used by a user with changing requirements

• systems used by a user working in a changing environment

• systems used by a user working in different system environments

Perceived benefits of Adaptive Hypertext Systems

• Users are able to interact with the system according to their needs and requirements

• Information accessed by users is adapted to their level of competence

• Users' view of the information space is adapted to their needs and requirements

• System may be able to automatically describe user interests, even if user is unable to do so

Examples of Adaptive Hypertext Systems

A detailed list is available at http://wwwis.win.tue.nl/ah/projects.html

• WebWatcher
• ELM-ART
• HyperContext

Domain-specific vs. Generic Adaptive Hypertext Systems

• Some AHSs (especially ITS-based AHSs) are domain specific, e.g., ELM-ART

• Others, e.g., WebWatcher, HyperContext, are domain-independent

• Major differences
  1. Identifiable range of users
  2. Extent to which domain knowledge can be represented and utilised
  3. Knowledge item inter-dependencies
  4. Reasonably limited number of goals
  5. Stability of user interest

AHS requirements

• Hypermedia

• User Model

• Information Retrieval (usually for generic AHSs)

• Knowledge representation (usually for domain-specific AHSs)

• Access path logging (depending on implementation)