2002 年 17 巻 3 号 p. 196-208
Recently, an ontology is expected to contribute to knowledge sharing and euse. It is,however, difficult to develop well-organized ontologies because the principles of ontology design are not clear enough. Therefore, a methodology for ontology design and a computer system supporting ontology design are needed. Our research goals include a methodology of ontology design, and development of an environment for building and using ontologies. Building an ontology requires a clear understanding of what can be concepts with what relations to others. An ontology thus focuses on “concepts” themselves rather than “representation” of them. Although several systems for building ontologies have been developed to date, they were not based on enough consideration of an ontological theory. We argue that a fundamental consideration of these ontological theories is needed to develop an environment for developing ontologies. Most of the previous ontologies, which are represented in frame-based languages,don't clearly deal with such concepts that need deep ontological investigation. Therefore we begin with a fundamental consideration of an ontological theory. We discuss mainly “role concept” and “relationship”, and consider how these ontologically important concepts should be treated in our environment. On the basis of the consideration we have designed and have developed an environment for building and using ontologies, named “Hozo”. This paper presents an outline of the functionality of Hozo. We focus on how it treats the relations and roles on the basis of fundamental consideration.