The training or T-group is an approach to human relations training which, broadly speaking, provides participants with an opportunity to learn more about themselves and their impact on others and, in particular, to learn how to function more effectively in face-to-face situations. It attempts to facilitate this learning by bringing together a small group of people for the express purpose of studying their own behavior as it occurs when they interact within a small group.

There are certain features that distinguish this type of group from a conventional group discussion. First, the training is primarily 'process oriented' rather than 'content oriented.' That is, the primary stress is on the feeling level of communication, rather than on the informational or conceptual level. This emphasis is accomplished by focusing on the 'here and now' behavior and themes in the group. Second, the training is not structured in a conventional manner. Opportunities are provided for the individuals to decide what they want to talk about, what kind of problems they wish to deal with, and what means they want to use in reaching their goals. No one tells them what they ought to talk about. As they concern themselves with the problems caused by this lack of direction, they begin to act in characteristic ways; some people remain silent, some are aggressive, some tend consistently to initiate discussions, and some attempt to structure the proceedings. With the aid of the facilitator, or group leader, these approaches or developments become the focal points of discussion and analysis. The facilitator draws attention to events and behavior in the group by occasional interventions in the form of tentative interpretations. Third, the heart of a T-group laboratory is found in small groups, allowing a high level of participation, involvement, and free communication. Intense involvement with the group is an essential feature of T-group programs, in contrast to other methods. This involvement may be of advantage in producing lasting changes in the attitudes and behavior of participants.

From a handout distributed at "Personal Growth Laboratory," sponsored each spring and autumn by Trenton State College, late 1970s to early 1980s.including 1981 to 1983. Source not attributed, but it was evidently taken from Cooper, C.L. & Mangham, I.L. (1971). T-groups: A Survey of Research. London: Wiley-Interscience, as quoted here.