A representation construct for roles

摘要

This paper introduces a construct for representing concepts together with the roles they can play. Its definition is based on facilities for representing generalization (is-a), classification (instance-of), property domains and actual properties. Although for illustation purposes a frame data model is used as a formal basis, the role construct can be adopted by any other data model (or knowledge representation model) which supports these facilities. The semantics of the role construct is specified by integrity constraints which cover, besides other aspects, a facility for sharing properties among roles. Operational characteristics are described with respect to the most relevant modification operations. A comparison with the various intuitive notions of roles which currently exist shows that they all can be reinterpreted in terms of the role construct and their meaning thus be made explicit.