1. n. A cohesive set of contributions made by a single, identifiable agent to a shared outcome.

Outcome. People sometimes talk about a role in a process, which focuses on the process as the context for the role. This gives process more emphasis than I like, and can give the impression that process is the goal. My definition emphasizes outcome. This reminds me that it’s ultimately the outcome, and our desire for that outcome, that motivates the role.

Shared. I considered dropping the word shared from the definition. I decided to retain it because when people talk about roles, it’s almost always in the context of an outcome to which many agents have contributed.

Single, identifiable agent. The agent may be a single person, an group of people, or some other, non-human contributor.

Cohesive. This means that the contributions share some essential quality. This word focuses on what is contributed, not on who makes the contribution.