A first component of an authority value is generated with reference to outbound links associated with a document and corresponding to a first subset of a plurality of documents. A second component of the authority value is generated with reference to a second subset of the plurality of documents that represent potential starting points for user sessions. A third component of the authority value is generated representing a likelihood that a user session initiated by any of a population of users will end with the document. At least one of the first, second, and third components of the authority value is computed with reference to user data relating to at least some of the outbound links and the second subset of documents.