Query Refinement based on Topical Term Clustering

We propose a method for supporting query refinement using topical term clusters. First, we propose a new term weighting method that can extract terms strongly related to a specific topic, because a document set retrieved with an ambiguous query may include divergent topics. Our formulation of term weighting is based on the statistics of term co-occurrence. Then, we generate term clusters using extracted terms, and rerank the documents in the search results by using each term cluster as a query. This clustering procedure is intended to isolate each topic as a set of related terms. In our experiments, we evaluated our term weighting method by checking: 1) whether each of the top-ranked document sets corresponds to one topic; and 2) whether some of the top-ranked document sets cover all the topics included in the synthesized document set. The results of our experiment show our method outperforms the existing term weighting methods MI, KLD, CHI-square and RSV.