1. A method comprising the steps of: receiving a particular query that comprises one or more terms; in response to receiving the particular query: making a first plurality of comparisons, wherein each comparison in the first plurality of comparisons is based on the particular query and a different query of a plurality of queries, wherein the number of the first plurality of comparisons and the number of the plurality of queries is the same; making a second plurality of comparisons, wherein each comparison in the second plurality of comparisons is based on the particular query and a different query of the plurality of queries; based on the first plurality of comparisons, generating a first numerical value; based on the second plurality of comparisons, generating a second numerical value that is different than the first numerical value; determining a ratio between the first numerical value and the second numerical value; and ranking documents in a document set based, at least in part, on the ratio; wherein the steps are performed by one or more computer systems.