Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for improving search results. In one aspect, a method includes receiving documents responsive to a query, each document having an associated score indicative of the document's relevance to the query. The method includes determining, for a plurality of the associated scores, a distribution of the scores along a dimension that measures trustworthiness of the scores. The method also includes reducing each of one or more of the plurality of associated scores by an amount determined based on the score's respective trustworthiness and properties of the distribution, and ranking the documents to account for the reduced scores.

Abstract: In general, in one aspect, embodiments of the invention feature a computer-implemented method for providing input to a document ranking process for ranking a plurality of documents, the document ranking process taking as input a quality of result statistic for an individual document in the plurality of documents, the plurality of documents having been identified in response to a query, the quality of results statistic being for the query and the individual document. The method for providing input can include, for a first document identified as a search result of a user-submitted query, scoring one or more other queries based upon a similarity to the user-submitted query, each of the one or more other queries being different from the user-submitted query.