27 巻 (2012) 3 号 p. 235-244
Is-a hierarchies form the foundation of ontologies. That is, is-a hierarchies in an ontology reflect how the ontology captures the essential conceptual structure of the target world. Therefore, in ontological theories, an is-a hierarchy should be single-inheritance because the essential property of things cannot exist in multiple. However, we cannot avoid multi-perspective issues when we build an ontology because the user often want to understand things from their own viewpoints. In order to tackle this multi-perspective issue, the authors take an approach of dynamically generating is-a hierarchies according to the viewpoints of users from an ontology using single-inheritance. This article discusses a framework for dynamic is-a hierarchy generation with ontological consideration on is-a hierarchies generated by it. Then, the author shows its implementation as a new function of Hozo and its applications to a medical ontology for dynamically generation of is-a hierarchies of disease. Through the function, users can understand an ontology from a variety of viewpoints. As a result, it could contribute to comprehensive understanding of the ontology and its target world.