All teams develop a set of roles and norms over time.
In task oriented teams, it is essential that the role structure enables the team to cope effectively with the requirements of the task. When the task is divisible and conjunctive, as are most of the important team tasks in our society, the assignment of roles to members who can perform them effectively is essential. Active consideration of the role structure can be an important part of a team building exercise. Even then, it is important that the norm governing the assignment of roles is understood and accepted by team members. Norms are the rules governing the behavior of team members, and include the rewards for behaving in accord with normative requirements, as well as the sanctions for norm violations.