Externalization of User Model in Mobile Services

In most personalized mobile services, the user model remains invisible, and users do not have control over it. Externalization of user models can allow users to get an overview the user model that is used for personalization, and adjust the profile and personalization effects to their needs and preferences. We have evaluated the interactive user model with 42 users, which were exposed to a prototype of interactive user model of personalized news service, for determining whether the proposed externalization, scrutability and privacy privileges were acceptable to the users. The purpose of the study was to find out if it is appropriate to present a user model on the mobile device and to control the sharing of the user model with the service provider. The conclusions show that the users expressed their general approval of the proposed privileges while making useful suggestions regarding improvements to the presentation and interface to the system.