2 User Profiles for Personalized Information Access

Abstract. The amount of information available online is increasing exponen-tially. While this information is a valuable resource, its sheer volume limits its value. Many research projects and companies are exploring the use of personal-ized applications that manage this deluge by tailoring the information presented to individual users. These applications all need to gather, and exploit, some in-formation about individuals in order to be effective. This area is broadly called user profiling. This chapter surveys some of the most popular techniques for collecting information about users, representing, and building user profiles. In particular, explicit information techniques are contrasted with implicitly col-lected user information using browser caches, proxy servers, browser agents, desktop agents, and search logs. We discuss in detail user profiles represented as weighted keywords, semantic networks, and weighted concepts. We review how each of these profiles is constructed and give examples of projects that employ each of these techniques. Finally, a brief discussion of the importance of privacy protection in profiling is presented