The Method of Query Expansion Based on Domain Ontology

An ontology is an explicit specification of a conceptualization. In this paper, A domain ontology is build based on Google page directory, used the relation among the concepts. We search the domains which the match concepts of the query terms belong to or include in the domain ontology. And we build a new domain ontology based on these domains and the match concepts. Two concepts of domain subordinate degree and domain inclusion degree are proposed. They are used to describe the degree of a domain belong to another domain and the degree of a domain includes another domain, respectively. And the domains which the domain belongs to or the domain includes can be confirmed by computing these two concepts. These domains are the results of the domain expansion or the domain reduction. In this method, the domain expansion and the domain reduction of the domain are completed. At the present time, the rdquorelation searchrdquo function of the search engineers (SE) can not precisely satisfy the userspsila need. In this paper, we propound a new method to realize the function of rdquorelation searchrdquo. We expand the user query terms using the results of the domain expansion and the domain reduction. This method can improve the precise of query expansion results by enhance the thematic of the user query terms.