<P>This book constitutes the refereed proceedings of the 29th annual European Conference on Information Retrieval Research, ECIR 2007, held in Rome, Italy in April 2007. The papers are organized in topical
sections on theory and design, efficiency, peer-to-peer networks, result merging, queries, relevance feedback, evaluation, classification and clustering, filtering, topic identification, expert finding, XML IR, Web IR, and
multimedia IR.</P>