User Modeling on the World Wide Web
                 Andrew Tomkins, Google

Online web pages today offer different levels of personalization, from
none at all, to simple personalization based on profiles or
user-specific data, to complex model-based personalization. In this
talk I discuss the nature and prevalence of pageviews from these
different classes. I also survey improvements due to personalization
in search, advertising, recommendations, and content optimization, and
describe a series of open research questions in the area.