Instance management problems in the role model of Hozo

Abstract

For knowledge (instances model) representation based on ontology and its use, it is desirable to understand phenomena in the target world as precisely as possible. The theory of ontology should reflect the understanding of them and provide a fundamental framework to manage the behavior of instances adequately. Hozo is known as an ontology-development tool with an ability to deal with roles and their instances. Although Hozo allows users to represent roles better than other existing tools, the underlying theoretical foundations are still unclear and there is some room for improvement concerning the generality of how to deal with instances of roles. Especially, establishment of the instance management method of role concept based on the ontological theory is an important subject. It is mainly concerned with handling of appearance and disappearance of role instances. This article discusses a refinement of role theory through investigation of problems such as distinction between constituent roles and general roles and what kind of constituent roles are needed in what situations are also discussed in detail. © 2008 Springer Berlin Heidelberg.