A Taxonomy of Roles

How many kinds of roles are out there? Although social and relational roles exist as dominant categories, we can see a lot of other kinds of roles which need closer attention. Although researchers on roles have been involved in defining roles that should nicely cover all kinds of roles, it is not clear how many kinds of roles there are[Masolo 2004][Mizoguchi 2007]. We have been investigating roles by observing typical examples that we believe they are roles. For example, a runner is definitely a role, but how about a breather? Both are roles as special type of doer role. For a runner, while he/she needs not to be so and he/she can start and/or stop being a runner, he/she must be a breather throughout his/her life. Being a breather is essential to being an animal which contradicts being a role. How about murderer role who has finished a killing event? If it means a person who has just committed a killing action, then what role is he playing after that? How about victim role? It has been killed by a murderer and hence there is no chance to be played because the player has been dead. These suggest that roles are still mysterious to us. The goal of this extended abstract is not to present a complete and rigid theory of roles but rather to stimulate the research on roles by presenting a few unaddressed issues. So, it is written aimed at being comprehensive and conceptual rather than narrow and rigid. We first build a taxonomy of roles and explore a temporal model of roles like murderer and victim which are dependent on occurrents as context. We have realized that although most of the roles are ongoing like walker and president, some are historical like murderer in the sense that roles are dependent on a past event. We discuss such a temporal issue of roles with a comprehensive taxonomy of roles.