SECCO: On Building Semantic Links in Peer-to-Peer Networks

Ontology Mapping is a mandatory requirement for enabling semantic interoperability among different agents and services relying on different ontologies. This aspect becomes more critical in Peer-to-Peer (P2P) networks for several reasons: (i) the number of different ontologies can dramatically increase; (ii) mappings among peer ontologies have to be discovered on the fly and only on the parts of ontologies ``contextual'' to a specific interaction in which peers are involved; (iii) complex mapping strategies (e.g., structural mapping based on graph matching) cannot be exploited since peers are not aware of one another's ontologies. In order to address these issues, we developed a new ontology mapping algorithm called Semantic Coordinator (SECCO). SECCO is composed by three individual matchers: syntactic, lexical and contextual. The syntactic matcher, in order to discover mappings, exploits different kinds of linguistic information (e.g., comments, labels) encoded in ontology entities. The lexical matcher enables discovering mappings in a semantic way since it ``interprets'' the semantic meaning of concepts to be compared. The contextual matcher relies on a ``how it fits'' strategy, inspired by the contextual theory of meaning, and by taking into account the contexts in which the concepts to be compared are used refines similarity values. We show through experimental results that SECCO fulfills two important requirements: fastness and accuracy (i.e., quality of mappings). SECCO, differently from other semantic P2P applications (e.g., Piazza, GridVine) that assume the preexistence of mappings for achieving semantic interoperability, focuses on the problem of finding mappings. Therefore, if coupled with a P2P platform, it paves the way towards a comprehensive semantic P2P solution for content sharing and retrieval, semantic query answering and query routing. We report on the advantages of integrating SECCO in the K-link+ system.