The document discusses ontology and how it relates to building user profiles and updating interest scores. It presents an approach where ontological profiles are built using a reference ontology to classify and categorize web pages. Each user profile consists of concepts from the reference ontology assigned interest scores that are initially set to one. The profiles are treated as networks of concepts and the interest scores are updated using a spreading activation algorithm based on the user's current interactions. When a user selects documents, their profile is updated by modifying the interest scores of existing concepts. This allows the most relevant pages to rise to the top based on the updated interest scores.