The power of feedback.

Social Network Analysis

I. the origin of species by means of natural selection

What is modal logic

Adaptive hypermedia is a relatively new direction of research on the crossroads of hypermedia and user modeling. Adaptive hypermedia systems build a model of the goals, preferences and knowledge of each individual user, and use this model throughout the interaction with the user, in order to adapt to the needs of that user. The goal of this paper is to present the state of the art in adaptive hypermedia at the eve of the year 2000, and to highlight some prospects for the future. This paper attempts to serve both the newcomers and the experts in the area of adaptive hypermedia by building on an earlier comprehensive review (Brusilovsky, 1996; Brusilovsky, 1998).

Adaptive Hypermedia

Hypermedia applications offer users the impression that there are many meaningful ways to navigate through a large body of information nodes. This rich link structure not only creates orientation problems, it may also be a source of comprehension problems when users follow paths through the information which the author did not foresee. Adaptive techniques have been used by a number of researchers [1, 2, 4, 5, 6, 7, 8, 9, 10, 17, 19, 20, 22] in an attempt to offer guidance through and orientation support for rich link structures. The majority of these adaptive hypermedia systems (AHS) have been used in educational applications. The terminology used in this paper also has an educational “flavor”. However, there are some adaptive on-line information systems (or “kiosk”systems), adaptive information retrieval systems, and other adaptive hypermedia applications. In this paper we describe a reference model for adaptive hypermedia applications, called AHAM, which encompasses most features supported by adaptive systems that exist today or that are being developed (and have been published about). Our description of AHS is based on the Dexter model [15, 16], a widely used reference model for hypermedia. The description is kept somewhat informal in order to be able to explain AHAM rather than formally specify it. AHAM augments Dexter with features for doing adaptation based on a user model which persists beyond the duration of a session. Key aspects in AHAM are: Paul De Bra is also affiliated with the University of Antwerp, Belgium, and with the “Centrum voor Wiskunde en Informatica” (CWI) in Amsterdam. yGeert-Jan Houben is also affiliated with the University of Antwerp, Belgium, and with Origin in Eindhoven. The adaptation is based on a domain model, a user model and a teaching model which consists of pedagogical rules. We give a formal definition of each of these (sub)models (but only describe the pedagogical rules informally throughexamples). We distinguish the notions of concept, page and fragment. In some AHS these notions are confused. We provide a formalism which lets authors write pedagogical rules (about concepts) in such a way that they can be applied automatically. We illustrate various aspects of AHAM by means of some features of some well-known AHS [6, 10].

AHAM: a Dexter-based reference model for adaptive hypermedia

AHA: an Adaptive Hypermedia Architecture

AHA!, the "Adaptive Hypermedia Architecture", was originally developed to support an on-line course with some user guidance through conditional (extra) explanations and conditional link hiding. This paper describes the many extensions and tools that have turned AHA! into a versatile adaptive hypermedia platform. It also shows how AHA! can be used to add different adaptive "features" to applications such as on-line courses, museum sites, encyclopedia, etc. The architecture of AHA! is heavily inspired by the AHAM reference model.

http://wwwis.win.tue.nl/~debra/ht03/pp401-debra.pdf

AHA! The adaptive hypermedia architecture

The navigational freedom in conventional hypermedia applications leads to comprehension and orientation problems (Nielsen 1990). Adaptive hypermedia attempts to overcome these problems by adapting the presentation of information and the overall link structure, based on a user model. This paper introduces a framework for adaptive hypermedia systems (AHS). It briefly describes some popular methods and techniques for adaptation. Examples and evaluations of existing AHS are used to illustrate the potential benefits of using adaptation in hypermedia applications.

Adaptive hypermedia: from systems to framework

The book presents an overview of the most fundamental aspects of the theory that underlies the Relational Database Model. It provides exact definitions of widely accepted concepts, and also covers some recent research topics, making the book very suitable in classes on database theory.

Paul De Bra

Papers

AHAM: a Dexter-based reference model for adaptive hypermedia

AHA: an Adaptive Hypermedia Architecture

AHA! The adaptive hypermedia architecture

Adaptive hypermedia: from systems to framework

The Structure of the Relational Database Model