Building and Exploiting User Models

This paper describes the issues involved in building and exploiting individual user models in order to guide the performance of an interactive system. A system called Grundy, that recommends novels to people, is described and analyzed as a forum in which to explore those issues. One of the major techniques exploited in Grundy is the use of stereotypes as a mechanism for quickly producing an initial approximation to a model of the user. Experiments with the system show that despite the fact that stereotypes are inherently imperfect, their use does contibute significantly to the system's ability to build useful models of its users.