A method and system for determining topical interest may include receiving signal information for a user of a document, the information including at least one signal value representing the user's activity with or relationship to the document. A document interest value based on the signal information for the user may be computed. Topic information for the document may be received, the information including at least one topic and a weight for each topic, where the topic relates to content of the document, and the weight represents how strongly the topic is associated with the document. An interest signature value of a first topic for the user may be updated by adding the product of the computed document interest value for the user for the document and the weight of the first topic for the document.