A task-centered approach for user modeling in a hypermedia office documentation system

Abstract

The development of user-adaptive systems is of increasing importance for industrial applications. User modeling emerged from the need to represent in the system knowledge about the user in order to allow informed decisions on how to adapt to match the user's needs. Most of the research in this field, however, has been theoretical, "top-down." Our approach, in contrast, was driven by the needs of the application and shows features of bottom-up, user-centered design.We have implemented a user modeling component supporting a task-based interface to a hypermedia information system for hospitals and tested it under realistic conditions. A new architecture for user modeling has been developed which focuses on the tasks performed by users. It allows adaptive browsing support for users with different level of experience, and a level of adaptability. The requirements analysis shows that the differences in the information needs of users with different levels of experience are not only quantitative, but qualitative. Experienced users are not only able to cope with a wider browsing space, but sometimes prefer to organize their search in a different way. That is why the user model and the interface of the system are designed to support a smooth transition in the access options provided to novice users and to expert users. Keywords:adaptation, adaptive interfaces, hypermedia and hypertext navigation, intelligent information retrieval, office / hospital documentation systems, task-based context for information retrieval, task-structures. Modeling and User Adapted Interaction, vol. 6, Nos. 2-3, 1996 . 2 Published in User IntroductionBrowsing is a useful technique for retrieving documents from data-bases (Thompson & Croft, 1989).It has been widely applied recently as hypertext and hypermedia systems have become increasingly popular (Begoray, 1990). The main cognitive advantage of this technique is that users in general are better able to recognize the information they want than to characterize it in advance. The disadvantages of browsing are that it is easy to get lost in a complex network of nodes representing documents and concepts and that there is no guarantee that browsing will be as effective as a more conventional search. If it offers a rich set of links, the system is responsible for helping the users understand what the links mean, how they might be used, and how to find their way in the network. Without this kind of help, browsing can take on the aspect of the user finding her way in a maze, where she can become hopelessly "lost in (hyper)space" (Conklin, 1987). User modeling can help in supporting the user's navigation and information retrieval. A user model is an explicitly represented collection of data about the user which allows the system to adapt its options to the needs of the user. The intensive development in the field of user modeling during the last decade (Kobsa & Pohl, 1994a) makes it possible to consider it as a practical approach for ensuring user-adapted information access in a hypermedia in...

Efficient techniques for adaptive hypermedia

“…This is not the same as user's knowledge of the subject (Vassileva, 1996). Sometimes, the user who is generally quite familiar with the subject itself is not familiar at all with the hyperspace structure.…”

User Models for Adaptive Hypermedia and Adaptive Educational Systems

“…Indeed, a few adaptive systems use some elements of this generalized vision to provide a more elaborated goal modeling. For example, some systems maintain a hierarchy of possible goals or tasks [198] and a few pioneer systems use probabilistic overlay modeling where each possible goal in the catalogue is represented by the system as a probability that it is the current user goal [63; 78; 126].…”

“…The user's background is a common name for a set of features related to the user's previous experience outside the core domain of a specific Web system (for example, the core domain of a city guide [36] is a specific city and its objects of interest; the core domain for a hospital information system [198] is a specific hospital, its objects and procedures). A range of backgrounds that have been used in adaptive Web systems includes the user's profession, job responsibilities, experience of work in related areas, and even specific view on the domain.…”

“…Another example is the categorizing of users by their language ability (i.e., native or non-native speakers), followed by choosing the appropriate version of the content for them [102]. Background information is used most frequently for content adaptation, although there are examples of the use of it within adaptive search [71; 121] and adaptive navigation support [198].…”

“…Another example is the categorizing of users by their language ability (i.e., native or non-native speakers), followed by choosing the appropriate version of the content for them [102]. Background information is used most frequently for content adaptation, although there are examples of the use of it within adaptive search [71; 121] and adaptive navigation support [198].By its nature, user background is similar to the user's knowledge of the subject (i.e., it is also mostly a measure of knowledge beyond the core domain area). However, the representation and handling of user background in adaptive systems is different.…”