The described subject matter provides systems and procedures to make query
similarity determinations, wherein the queries are used in information
retrieval operations. A same document and/or multiple similar documents
are identified that have been selected by a user in response to multiple
queries. Responsive to identifying the same document and/or the similar
documents, a query cluster is generated that indicates that the queries
used to obtain the same and/or similar documents. This is accomplished in
a manner that is independent of whether individual ones of the queries
are compositionally similar with respect to other ones of the queries.