that can be shared by all the members to encourage involvement. Developmental groups encourage the members to develop sequentially organized social interaction skills with the other members. Parallel groups are made up of clients doing individual tasks side by side. Project groups emphasize task accomplishment. Some interaction may be built in, such as shared materials and tools and sharing the work. Egocentric cooperative groups require the members to select and implement the task. Tasks are longer term and socialization is required. Cooperative groups require the therapist only as an advisor. Members are encouraged to identify and gratify each other's social and emotional needs in conjunction with task accomplishment. The task in a cooperative group may be secondary to social aspects. Mature groups involve the therapist as a co-equal member. The group members take on all leadership roles in order to balance task accomplishment with need satisfaction of the members. Self-help groups are supportive and educational, and focus on personal growth around a single major life disrupting problem (for example, Alcoholics Anonymous). Support groups focus on helping others in a crisis and continue to do so until the crisis is gone and is usually before the self-help group. Advocacy groups focus on changing others or changing the system, rather than changing one's self: "getting one from point A to point B". Psychotherapy groups focus on helping individuals in the present that have past conflicts which affect their behavior. Variations Many varieties of T-groups have existed, from the initial T-groups that focused on small group dynamics, to those that aim more explicitly to develop self-understanding and interpersonal communication. Industry also widely used T-groups, particularly in the 1960s and 1970s, and in many ways these were predecessors of current team building and corporate culture initiatives. A current T-group version that addresses the issue of openness is the "Tough Stuff™" workshop of Robert P. Crosby and his associates. Crosby trainers carefully focus the group on their experience of their immediate interactions and group dynamics, and away from openness in the form of personal stories. Applying the behavioral communication model of John L. Wallen, The Interpersonal Gap, the participants are given a structure for talking about and learning from their interactions. The Crosby T-group also puts much of the feedback task in the hands of the participants. Using Wallen's model and behavioral skills, the participants are encouraged to give and receive feedback throughout the process,