Patent attributes
Methods, systems, and apparatus, including computer programs encoded on computer storage media, for document ranking. One of the methods includes receiving a request for one or more documents, obtaining a set of documents responsive to the request, and obtaining, from a user profile associated with a source of the request, representations of one or more topics of interest to a user. The method also includes selecting, from the set of documents, at least one document associated with a particular topic that matches at least one of the one or more topics of interest to the user, for the at least one selected document, obtaining a value corresponding to an inverse document frequency of documents associated with the particular topic in a corpus of documents, and generating a score for the at least one document based at least in part on the value corresponding to the inverse document frequency.
