WWW '05 International Workshop on Innovations in Web Infrastructure (IWI '05)
May 10, 2005, Chiba, Japan.

Emergence of Spontaneous Order Through Neighborhood Formation in Peer-to-Peer Recommender Systems

Ernesto Diaz-Aviles, Lars Schmidt-Thieme, Cai-Nicolas Ziegler


The advent of the Semantic Web necessitates paradigm shifts away from centralized client/server architectures towards decentralization and peer-to-peer computation, making the existence of central authorities superfluous and even impossible. At the same time, recommender systems are gaining considerable impact in e-commerce, providing people with recommendations that are personalized and tailored to their very needs. These recommender systems have traditionally been deployed with stark centralized scenarios in mind, operating in closed communities detached from their host network’s outer perimeter. We aim at marrying these two worlds, i.e., decentralized peer-to-peer computing and recommender systems, in one agent-based framework. Our architecture features an epidemic-style protocol maintaining neighborhoods of like-minded peers in a robust, self-organizing fashion. In order to demonstrate our architecture’s ability to retain scalability, robustness and to allow for convergence towards high-quality recommendations, we conduct offline experiments on top of the popular MovieLens dataset.