Introduction to Special Issue on Adaptive Hypermedia

Already in the earliest ideas leading up to hypermedia, starting with Vannevar Bush's Memex (Bush 1945), the personal view of and access to and through information was a key aspect of hypertext and hypermedia research. In traditional hypertext, personalization was user-driven: the existence of links enabled each user to follow his/her own path through the hyperspace. However, since about 1990, the topic of system-driven personalization has started to receive more attention. Instead of just the user selecting a personal path through hyperspace personalized, dynamic and/or adaptive hyperdocuments change the hyperspace itself as the user is traversing (or otherwise using) it.

The mid-1990s mark the start of serious research into hypertext, hypermedia, and later Web personalization and adaptation and the emergence of an active adaptive hypermedia community with workshops on adaptive hypermedia at the User Modeling, the ACM Hypertext and the World Wide Web conferences. This has culminated in the start of a separate bi-annual conference series on Adaptive Hypermedia, the first one in Trento, Italy, in August 2000. Adaptive Hypermedia conferences alternated with the User Modeling conferences, showing, year by year, an increasing overlap in interest and attendance as adaptation heavily relies on user modeling and user modeling is almost always done in order to achieve some form of adaptation or personalization. The year 2008 marked the end of the separate conference series, and the merger of the Adaptive Hypermedia and User Modeling events into a new annual conference on User Modeling, Adaptation and Personalization. Adaptive Hypermedia has come of age and become an important component of the global research on adaptation and personalization. This special issue, third in the line of NRHM special issues devoted to Adaptive Hypermedia (after NRHM 4, 1998 and NRHM 10(1), 2004) attempts to present a snapshot of Adaptive Hypermedia research in this important point of time.

Building on recent Adaptive Hypermedia conferences and ACM Hypertext conferences, this special issue brings together an interesting mix of recent developments. Even though unplanned at the time of soliciting papers, we ended up with an outstanding mix of AH-related topics, describing technical issues as well as the usability of adaptive applications.

The first paper in this special issue brings together the past and future. Appropriately titled AH 12 years later: a comprehensive survey of adaptive hypermedia methods and techniques (Knutov, De Bra, Pechenizkiy), it reflects on the AH research since the seminal paper (Brusilovsky 1996) “Methods and techniques of adaptive hypermedia” that has become a standard reference in AH literature. The new paper not only revisits (and updates) the taxonomy of adaptation methods and techniques but also compares AH models and AH systems in order to distill common architectures and technologies. By posing (and partially answering) questions about adaptation: what, to what, why, where, when and how, the paper shows what is needed in a generic future-proof state of the art AH system. This paper will lead the way to a common understanding of the AH field.

While the first paper mainly targets the part of AH research where content, navigation, and adaptation are assumed to be the result of work by a (human) author, the second paper introduces adaptation in the area of Web Engineering. The field of Web Information Systems deals with making information systems accessible through Web-based technology. Content and navigation are generated and not authored in these systems. The same types of personalization/adaptation are possible but these too need to be generated. The paper, Aspect-Oriented adaptation specification in web information systems: a semantics-based approach (Casteleyn, Van Woensel, van der Sluijs, Houben), relies on semantic descriptions of both the domain data and user and context characteristics in order to generate adaptation. The paper uses an aspect-oriented approach to avoid the common problem that adaptation engineering is (too) closely intertwined with the regular Web design process. In this approach the selection of elements and the actions to be performed upon them are encapsulated in “aspects”, thereby separating the implementation of adaptation from the application design.

The third paper, Topic development pattern analysis-based adaptation of information spaces (Ahmed, Candan, Han, Qi), targets the issue of adaptation to visually impaired users. Technology to support reading and navigating in hyperdocuments by visually impaired users already exists but this paper targets the problem of skimming which is especially difficult in large documents. The paper focuses on two specific challenges: content-segmentation and content-reorganization. The paper introduces OASIS, an adaptable system that uses the topic segmentation method, CUTS, to identify topic development patterns and perform text segmentation. This method does not rely on natural language understanding in order to perform segmentation, summarization and also the generation of a “virtual book” with content from different sources.

Finally, the fourth paper studies the effect of adaptation on the usage of adaptive hypermedia applications. As the title Addictive links: the motivational value of adaptive link annotation (Sosnovsky, Yudelson, Brusilovsky), suggests, this paper reports on a newly discovered effect of adaptation in an e-learning context: it turns out that adaptive navigation support through link annotation stimulates users to work (more) with non-mandatory educational content. Although the effect was confirmed as significant in several studies, the authors call for further research to determine the true reason why adaptation produces this stimulating effect.

This brings us back to one of the common key ingredients of all four papers of this special issue: they all point the way for future research in all corners of the AH research field, beyond the specific research being undertaken by the authors of the papers.

In a final note we would like to thank Doug Tudhope and Daniel Cunliffe for enabling us to put together this special issue and for their support throughout the stressful reviewing and revision process. The call for contributions to this special issue attracted more quality papers than we could fit in a single issue, both in terms of space and of the publication timeframe. So do watch future issues for more contributions in the field of adaptive hypermedia as well.

Organizational issues

From 2009, NRHM appears three times a year. Authors are welcome to submit papers relevant to the general scope of the NRHM at any time. NRHM submissions and reviewing are conducted via ScholarOne's Manuscript Central, the Taylor & Francis journal management system: http://mc.manuscriptcentral.com/tham.

The journal's website http://www.informaworld.com/tham links to Manuscript Central via online submissions. Online articles are available from the website in both PDF and HTML formats. The Introduction to an NRHM issue is available free, while articles can be viewed by subscribers or purchased individually. We welcome proposals for future Special Issue themes. We are interested in exploiting possibilities of the digital medium and authors who wish to include a digital component are encouraged to contact the Editor with questions.

Paul De Bra

Department of Computer Science

Eindhoven University of Technology

Eindhoven, the Netherlands

Email: [email protected]

Peter Brusilovsky

School of Information Sciences

University of Pittsburgh

Pittsburgh, USA

Email: [email protected]