A Cluster Based Pseudo Feedback Technique Which Exploits Good and Bad Clusters

In the last years, cluster based retrieval has been demonstrated as an effective tool for both interactive retrieval and pseudo relevance feedback techniques. In this paper we propose a new cluster based retrieval function which uses the best and worst clusters of a document in the cluster ranking, to improve the retrieval effectiveness. The evaluation shows improvements in some standard TREC collections over the state-of-the-art techniques in precision and robustness.