Using Combination of Evidence for Term Expansion

Expanding a user query automatically with terms taken from documents that are most similar to the query is a reliable way of finding more relevant documents. To date most approaches to this problem have focused on modifying the query. In this paper we argue that it is useful to create a new query from similar documents, rank both the user query and the new query, and combine the evidence. We show that there are both theoretic and practical advantages in this process.