Proceedings of the 2nd Workshop on Adaptive Hypertext and Hypermedia
HYPERTEXT'98, Pittsburgh, USA, June 20-24, 1998

Adaptable and Adaptive Information Access for All Users, Including Disabled and Elderly People

Alfred Kobsa
GMD FIT, 53754 St. Augustin, Germany

Constantine Stephanidis
ICS-FORTH, 71110 Heraklion, Crete, Greece
Abstract: One of the main objectives of the AVANTI project is to extend the scope of current research on adaptability and adaptivity, in that the needs of disabled and elderly users are also taken into account. Existing user modeling tools can be fruitfully employed in this endeavor.


Research on adaptable and adaptive interactive software systems aims at rendering these systems tailorable to the needs of different user groups. Those end-user groups who have been considered so far were nearly always comprised of users with "average" physical and cognitive abilities. People with special needs (including disabled people, and to some extent also elderly people) should, however, also be given the opportunity to access computers, since they are indispensable at many workplaces and increasingly are becoming a medium through which important services at home and in public places can be accessed. For many categories of disabled people, computers may even allow for (partial) compensation of their handicaps.

Computer access for the handicapped has been a research issue for many years. Considerable effort has been put into making software systems accessible by user categories other than the ones they were -originally- designed for (e.g. for visually or motor impaired users) and into developing databases with information for disabled people that supplements already available data (e.g. information on wheelchair accessibility of public transportation, or verbal descriptions of paintings in major museums). These solutions mostly address a small number of disabled users and are, therefore, usually fairly expensive due to the restricted customer base. It seems, however, that techniques from the area of adaptable and adaptive interactive systems can be extended in such a way that they permit tailoring generic interactive software systems to all users, including the disabled and the elderly. This approach is not only theoretically more satisfactory, but may also be economically more viable than isolated dedicated solutions.

Application domain and user needs

The AVANTI prototype [1, 4, 6, 8] is a distributed system that provides hypermedia information on places of interest, public transportation and public buildings in a city. The system is accessible from users' homes and from public information booths. The intended users are tourists and citizens with different aims, interests, experience and abilities (including restricted sensory and motoric abilities).

These different users have varying needs with respect to information content as well as information presentation. For example, information for lay-persons should not be very technical and detailed but instead be augmented by explanations and by visual material [2]. Information for motor-impaired users should be supplemented, e.g., by data on wheelchair accessibility. Information for blind users should be complemented by data on services available for blind users. Moreover, such material cannot be presented visually, but only acoustically or via special output devices for the blind.

Technical approach

Information in AVANTI is presented in hypermedia form on the World Wide Web. The description of each hypermedia page contains information options (like optional information on wheelchair accessibility) as well as information alternatives (like technical vs. non-technical descriptions, or a picture of a painting vs. its verbal description). Additionally, the objects with which the user interface is constructed can be presented differently to the user (e.g., a pull-down menu can be presented visually or acoustically [5, 6]).

The selection of options and the preference of alternatives over the default is controlled by the user. If permitted by him or her, the system can, in most cases, choose options and pre-select alternatives automatically (either can be overridden by the user). The selections are made based on a central user model. Information about users is gathered with initial interviews and by monitoring users' interaction with the system. Pending results on user acceptability, smart cards will also be considered as an input device. Secondary information is derived with inference rules and stereotypes. Methodologies and tools for developing a user modeling server [3] and for producing adaptable and adaptive interfaces [7, 9] are being employed in the project.

The iterative evaluation of the AVANTI prototype is now nearing its completion. In particular, adaptability and adaptivity in the user interface and the information content levels are the subject of a separate, specifically designed part of the evaluation procedure, which is currently under way [10].


The ACTS AC042 AVANTI project "AdaptiVe and Adaptable INteractions to Multimedia Telecommunications ApplIcations", is partially funded by the European Commission (DG XIII). The AVANTI consortium comprises: ALCATEL Siette (Italy) - Prime contractor; CNR-IROE (Italy); ICS-FORTH (Greece); GMD (Germany); University of Sienna (Italy); MA Systems (UK); MATHEMA (Italy); VTT (Finland); ECG (Italy); University of Linz (Austria); TELECOM ITALIA (Italy); EUROGICIEL (France).



[1] Fink, J., A. Kobsa and J. Schreck (1997): Personalized Hypermedia Information through Adaptive and Adaptable System Features: User Modeling, Privacy and Security Issues. In: A. Mullery, M. Besson, M. Campolargo, R. Gobbi and R. Reed, eds.: Intelligence in Services and Networks: Technology for Cooperative Competition. Berlin Heidelberg: Springer, 459-467. 

[2] Kobsa, A., A. Nill and J. Fink (1997): Hypertext and Hypermedia Clients of the User Modeling System BGP-MS. In M. Maybury, ed.: Intelligent Multimedia Information Retrieval. Boston, MA: MIT Press.

[3] A. Kobsa, W. Pohl (1995): The User Modeling Shell System BGP-MS. User Modeling and User-Adaptive Interaction 4(2), 59-106.

[4] A. Nill (1997): Providing Useable and Useful Information by Adaptivity and Adaptability. Proceedings of the Flexible Hypertext Workshop, 8th ACM International Hypertext Conference (Hypertext'97), Southhampton, England.

[5] C. Stephanidis, Y. Mitsopoulos (1995): INTERACT: An Interface Builder Facilitating Access to Users with Disabilities. Proc. HCI International '95, Tokyo, Vol. 2, 923-928.

[6] C. Stephanidis, A. Paramythis, M. Sfyrakis, A. Stergiou, N. Maou, A. Leventis, G. Paparoulis, C. Karagianidis (1998): "Adaptable and Adaptive User Interfaces for Disabled Users in AVANTI Project", 5th International Conference on Intelligence in Services and Networks (IS&N '98), "Technology for Ubiquituous Telecom Services", Antwerp, Belgium.

[7] Stephanidis, C., Savidis, A., & Akoumianakis, D. (1997). Unified interface development: Tools for constructing accessible and usable user interfaces: Tutorial No. 13 in HCI International 97 Conference. Available at: publications.html

[8] A. Bini, P.L.Emiliani (1997): Information about mobility issues: The ACTS AVANTI project. 4th European Conference for Advancement of Assistive Technology (AAATE '97), Porto Carras, Greece, 29 September - 2 October 1997.

[9] A. Savidis, A. Paramythis, D. Akoumianakis, C. Stephanidis, "Designing user-adapted interfaces: the unified design method for transformable interactions", ACM Conference on Designing Interactive System: Processes, Methods and Techniques (DIS '97), Amsterdam, The Netherlands, 18-20 August 1997, 323-334.

[10] AVANTI Deliverable DE030 "Global evaluation of the experiments", forthcoming public deliverable of the AVANTI consortium, August 1998.