user actions at different levels of abstractions. Using the ontology's concepts and relations, we capture the multitude of user interests expressed by a visit to one page. We employ our ideas in an application of SEAL, a framework for semantic portals that uses Semantic Web technologies to support communities of interest. Different realizations of semantically enriched user tracking are discussed and related to other approaches. We describe first results from a prototypical system, and discuss benefits of Conceptual User Tracking for Web usage mining. Keywords Web (Usage) Mining, User tracking, Semantic Portal, Ontology