Combining multiple evidence from different types of thesaurus for query expansion

Automatic query expansion has been known to be the most important method in overcoming the word mismatch problem in information retrieval. Thesauri have long been used by many researchers as a tool for query expansion. However only one type of thesaurus has generally been used. In this paper we analyze the characteristics of different thesaurus types and propose a method to combine them for query expansion. Experiments using the TREC collection proved the effectiveness of our method over those using one type of thesaurus.