The SEWASIE Multi-agent System

Data integration, in the context of the web, faces new problems, due in particular to the heterogeneity of sources, to the fragmentation of the information and to the absence of a unique way to structure and view information. In such areas, the traditional paradigms, on which database foundations are based (i.e. client server architecture, few sources containing large information), have to be overcome by new architectures. The peer-to-peer (P2P) architecture seems to be the best way to fulfill these new kinds of data sources, offering an alternative to traditional client/server architecture. In this paper, we envisage a multilevel architecture, with local nodes and communities strongly tied with a semantic context which is well defined and offers a globally integrated ontology to represent everything. At a wider level the relationships among distinct nodes are established by means of weaker mappings.