1. A computer-based method for creating an expanded lexicon for use in searching, comprising: identifying a second document from a query log using a document pattern extracted from a set of one or more first documents in the query log, using a computer-based processor, where the set of one or more first documents is identified using a set of one or more first lexicon elements in a set of one or more first queries; and extracting a second lexicon element for the lexicon from a second query identified using the second document from the query log.