The CIKM 2006 Workshop on Information Retrieval in Peer-to-Peer Networks

Information Retrieval (IR) in distributed and decentralized environments has become an active field of research during the last years. Recently, Peer-to-Peer (P2P) networks have emerged as an attractive architectural paradigm for IR, both for technical and economic reasons. P2P networks are distributed and self-organizing systems that support resource sharing. For this reasons, they are promising building blocks for next-generation search engines that will have to deal with huge amounts of heterogeneous (e.g. textual, multimedia, audiovisual) and continuously changing data. Moreover, P2P search is appealing from an economic perspective since it requires minimal in-place infrastructure and maintenance, yet facilitating higher diversity in contents and search methods. However, P2P retrieval methods still pose a lot of research challenges. Search methods are typically limited to simple keyword queries and the use of advanced retrieval models is quite constrained. There is an ongoing debate within the research community on the efficiency and scalability of such approaches, as well as effectiveness and applicability of traditional models in this new environment. P2PIR 2006, the third Workshop on Information Retrieval in Peer-to-Peer Networks was held on November 11, 2006 in conjunction with CIKM 2006. This year’s workshop was a team effort continuing the tradition of past workshops, the Workshop on Information Retrieval in Peer-to-Peer Networks which was collocated with SIGIR in 2004 and with CIKM in 2005, and the Workshop on Heterogeneous Distributed Information Retrieval collocated with SIGIR in 2005. The workshop attracted around 15 researchers from the domains of IR and databases working on distributed and decentralized IR systems. The call for papers attracted 13 submissions from Asia, Europe, and the United States. The program committee accepted 7 scientific papers presenting original solutions for resource selection and query routing, indexing techniques in decentralized environments, and implementations of P2P retrieval engines. The workshop was opened by Fausto Rabitti, research director at ISTI-CNR, Pisa, Italy, who gave an invited talk on the future of P2P audiovisual search and provoked a lively discussion that continued throughout the paper presentations and the closing panel discussion. Paper presentations were divided into the following sessions: Resource selection, Similarity search, and Systems and applications. The panel discussion was organized around the usage scenarios, and economic and social factors steering the adoption of the P2P technology in the field of IR. The invited talk slides and workshop program are available online from