Modeling the User Knowledge by Belief Networks FIORELLA DE ROSIS,* SEBASTIANO PIZZUTILO** ALESANDRA RUSSO*** Dipartimento di lnformatica, Universitd di Bari, Italy DIANE C. BERRYt Department of Psychology, University of Reading, UK and F. JAVIER NICOLAU MOLINA~r INSERM- U88, Paris, France (Received 28 January, 1992; in final form 25 August, 1992) and Abstract. This paper describes the user modeling component of EPIAIM, a consultation system for data analysis in epidemiology. The component is aimed at representing knowledge of concepts in the domain, so that their explanations can be adapted to user needs. The first part of the paper describes two studies aimed at analysing user requirements. The first one is a questionnaire study which examines the respondents' familiarity with concepts. The second one is an analysis of concept descriptions in textbooks and from expert epidemiologists, which examines how discourse strategies are tailored to the level of experience of the expected audience. The second part of the paper describes how the results of these studies have been used * Fiorella de Rosis is associate professor of Computer Science at the University of Bad. For several years after her thesis in Theoretical Computer Science at the University of Rome, she did research in Medical Informatics. From 1986, her primary interests lie in the area of uncertainty, task and user modeling, adaptivity of interaction. She was responsible for the Bari University group, in the European Community Project EPIAIM. ** Sebastiano Pizzutilo is a senior researcher in Computer Science at the University of Bari, where he received his degree in Computer Science in 1975. He teaches computer architectures within the Bad university curriculum in Computer Science. His current research includes the fields of object-oriented data and knowledge bases and of intelligent interfaces. *** Alesandra Russo is a PhD candidate in Computer Science at the Imperial College of Science and Technology in London. She received her degree in Computer Science from the University of Bad in 1990, after having prepared a thesis at the University of Paris 5, in the framework of an ERASMUS Project. Diane Berry is a lecturer in psychology at the Universityof Reading. Prior to this she was a research fellow and lecturer in psychology at Balliol Conege, Oxford. She has a first class degree in psychology and a doctorate in experimental psychology. For the last 10 years, she has been researching in the area of human computer interaction. t~ F. Javier Nicolau Molina is a researcher at INSERM in Paris. He received his degree in Computer Science at the University of Barcelona in 1986 and a Master(DEA) in Medical Informatics from the University of Paris 5 in 1989. In the EPIAIM Project he was responsible for building the user modeling module and the generator of adaptive messages in an object- oriented language. User Modeling and User-Adapted Interaction 2: 367-388, 1992. ~) 1992 Kluwer Academic Publishers. Printed in the Netherlands.