1. A method in a computer system for calculating importance of a document, the method comprising: providing user, query, and document triplets indicating that the user submitted the query and that the user selected the document from a result of the query; receiving an input user, an input query, and an input document as an input triplet, the input query having been submitted by the input user and the input document being a document of a search result for the input query; and determining a probability that the user will find the input document important by performing a smoothing of the provided triplets to account for triplets not provided and calculating the probability based on the smoothing.