12. The system of claim 11 wherein the operations further comprise: accessing at least one second query reformulation path; comparing the query reformulation path with the at least one second query reformulation path; recognizing a pattern common to the query reformulation path and the at least one second query reformulation path; and generating a query reformulation pattern based on the recognized pattern.
12. The system of claim 11 wherein the operations further comprise: accessing at least one second query reformulation path; comparing the query reformulation path with the at least one second query reformulation path; recognizing a pattern common to the query reformulation path and the at least one second query reformulation path; and generating a query reformulation pattern based on the recognized pattern. 13. The system of claim 12 wherein generating a query reformulation pattern includes generating a query reformulation pattern in which at least a portion of the query reformulation pattern is related to higher level semantics.