US Patent 7603348 System for classifying a search query

A system is described for classifying a search query. The system may create a machine learning classifier function that may be “trained” by a plurality of categorized queries within a query taxonomy. The system may represent the queries as term vectors and input the term vectors to the machine learning classifier function to generate a value that may correspond to a particular category within the query taxonomy. The system may regularize the machine learning classifier function based on user search click data to improve the classifying accuracy.