Ontological analyses of roles

This paper discusses roles from ontological point of views. We first propose a most general type including roles and role-like entities in a new way. Then, we discuss ongoing property of roles to in-depth understand temporal aspects of roles. We identify two kinds of roles: original roles and derived roles. Our new findings in this research include all original roles are ongoing and all the derived occurrent-dependent roles are either retrospective or prospective. Finally, we propose a temporal model of derived roles.