摘要: Thesaural relations have long been used in information retrieval to enrich queries; they sometimes cluster documents as well. Sometimes the first query an system yields no results at all, or, what can be even more disconcerting, many thousands of hits. One solution is rephrase query, improving choice terms by using related different types. A collection often called a thesaurus. This chapter describes lexical-semantic that building thesauri and summarizes some effects these relational experiments.