Working Group
This is a group for which there is no significant incremental performance need or opportunity the would require it to become a team. The members interact primarily to share information, best practices, or perspectives and to make decisions to help each individual perform within his or her area of responsibility.
Pseudo-team
This is a group for which their could be a significant, incremental performance need or opportunity, but it has not focused on collective performance and is not really trying to achieve it. It has no interest in shaping a common purpose or set of performance goals, even though it may call itself a team. Pseudo teams are the weakest of all groups in terms of performance impact.
Potential Team
This is a group for which there s a significant, incremental performance need, and that really is trying to improve its performance impact. Typically, however, it requires more clarity about purpose, goals or work-products and more discipline in hammering out a common working approach. It has not yet established collective accountability.
Real Team
This is a small number of people with complementary skills who are equally committed to a common purpose, goals, and working approach for which the hold themselves mutually accountable.
High Performance Team
This is a group that meets all the conditions of real teams, and has members who are also deeply committed to each other's personal growth and success. That commitment usually transcends the team. The high performance team significantly outperforms all other like teams, and outperforms all reasonable expectations given its membership.
(J.R. Katzenbach & D.K. Smith, Wisdom of Teams, 1993)