From Classic User Modeling to Scrutable User Modeling

User Modeling still represents a key component for a large number of personalization systems. Maintaining a model for each user, a system can suc- cessfully personalize its contents and use available resources accordingly. On- tologies, as a shared conceptualization of a particular domain, can be suitably exploited also in this area. In this paper we explain some concepts about user modeling, particularly focusing on scrutability and its importance in ontology- based user modeling systems