8. A computer-readable storage medium comprising computer-program instructions that when executed by a processor perform operations of: identifying first and second search-result documents respectively resulting from first and second queries of a plurality of queries as being a same document or similar documents, the identifying including determining the similar documents based on a proportionality of commonly selected individual documents or based on a hierarchical positioning between individual ones of a plurality of documents commonly selected across the queries, and the first and second queries being separate and distinct from one another; responsive to identifying the first and second search-result documents as being the same document or similar documents, generating a query cluster including the first and second queries to indicate that the first and second queries are similar even if the first and second queries possess different compositions with respect to one another, wherein the query cluster is used to disambiguate a word or phrase in a query of the queries; and constructing a thesaurus comprising a plurality of synsets, wherein each synset comprises one or more query clusters.
8. A computer-readable storage medium comprising computer-program instructions that when executed by a processor perform operations of: identifying first and second search-result documents respectively resulting from first and second queries of a plurality of queries as being a same document or similar documents, the identifying including determining the similar documents based on a proportionality of commonly selected individual documents or based on a hierarchical positioning between individual ones of a plurality of documents commonly selected across the queries, and the first and second queries being separate and distinct from one another; responsive to identifying the first and second search-result documents as being the same document or similar documents, generating a query cluster including the first and second queries to indicate that the first and second queries are similar even if the first and second queries possess different compositions with respect to one another, wherein the query cluster is used to disambiguate a word or phrase in a query of the queries; and constructing a thesaurus comprising a plurality of synsets, wherein each synset comprises one or more query clusters. 9. The computer-readable medium of claim 8 , wherein the computer-executable instructions further comprise instructions for determining that the first and second queries are similar based on similar keyword or phrase composition.