UCSC at Relevance Feedback Track

The relevance feedback track in TREC 2009 focuses on two sub tasks: actively selecting good documents for users to provide relevance feedback and retrieving documents based on user relevance feedback. For the first task, we tried a clustering based method and the Transductive Experimental Design (TED) method proposed by Yu et al. [5]. For clustering based method, we use the K-means algorithm to cluster the top retrieved documents and choose the most representative document of each cluster. The TED method aims to find documents that are hard-to-predict and representative of the unlabeled documents. For the second task, we did query expansion based on a relevance model learned on the relevant documents.