Data-Sharing P2P Networks with Semantic Approximation Capabilities

The synergy between Peer-to-Peer systems and Semantic Web technologies has paved the way for large-scale sharing of semantically rich data, usually represented through schemas like, for instance, RDF or ontologies.Because of the lack of common understanding of the vocabulary used by peers, the resulting heterogeneity of data representations opens new challenges as to the efficient and effective retrieval of relevant information.In this paper, as opposed to viewing semantic misalignment as a limit for interoperability, we leverage on the presence of semantic approximations between the peers' schemas as a means for giving effective hints along two directions: 1) for query routing purposes, to identify the peers which best satisfy the user's requests, and 2) for making users aware of the relevance of the returned answers through a ranking mechanism which promotes the most semantically related results.