A New Approach to Expand User's Query in Domain Specific Search Engines

Most of popular search engines accept user's query as a set of keywords. But, keywords are not powerful enough for comprehensive representation of user request. In this paper, we introduce “Domain Specific Concept Hierarchy (DSCH)” as a specialization of concept hierarchies. Then we propose a new algorithm for automatic construction of DSCH. Using this hierarchy in a domain specific search engine, search engine expands the user's query by adding a set of conceptually related terms to query. The proposed algorithm has been implemented and the results are presented. We have used DSCH in AKU-CS domain specific search engine. The result shows significant improvement in quality of results of search engine so that it returns results that are more relevant to the user’s query with higher ranks in comparison with original search engine, which does not use query expansion. We used Cora search engine that is a computer science papers search engine as original system.