关键词: 信息需求域, 内涵, 外延, 界模型, 信息检索, 参数优化

Abstract: For information retrieval system, how to understand accurately and express user’s information need is the key to improve information retrieval results. This paper analyzes natural language’s connotation and denotation, calculates the upper bound, lower bound of information need, determines the information need domain and introduces an expression of user information need called Bound model. In information retrieval, similarity between document and the information need domain is defined and calculated, and documents are sorted according to the similarity. Experiments done using Lemur tools show that the Bound model has good retrieval results. This paper optimizes parameter of the similarity in Bound model further and gets better retrieval results.

Key words: information need domain, connotation, denotation, Bound model, information retrieval, parameter optimization