According to practicing group psychotherapists, the two most valued components of training for group psychotherapy are: (1) the opportunity to conduct a therapy group under supervision, and (2) participation in experiential training (Dies 1974). It is no wonder, then, that a large spectrum of experiential training models has emerged (Lakin, Lieberman, and Whitaker 1969). What is learned from the various models relates to the milieu, the leader, and the group composition (Stone and Green 1978), and in part depends on the particular training format. In contrast to descriptions of training, however, is the relatively limited formal evaluation of the learning which occurs in these programs. This paper will focus on an evaluation of the learning which took place during the group dynamics component of group psychotherapy training. The effect on learning of variations in format in which the leader is either silent or explicates group processes was tested.