Interoperation, Mediation, and Ontologies

In this paper we address the problem of interoperation at a semantic level. We assume that emerging standards will solve most of the syntactic infrastructure problems that exist today. However, interoperation has to deal with sources from diiering domains, and their semantic diierences. We present mediation as the principal means to resolve problems of semantic interoperation. Since the number of domains is large we cannot foresee a global solution to that problem, and hence will have to deal with domain interaction incrementally, and bring domains together as and when needed. To formalize the processing in mediation we will need formal models of the source domains, of the articulation points, and of the customer needs. We expect to capture these models using tools developed in the ARPA knowledge-sharing projects. The basis for these models are domain ontologies. We propose a knowledge-based algebra to manage the interoperation of information from diierent domains. Several research issues that arise in the formalization of semantic interoperation are indicated.