Confusion has resulted from a lack of clarification of the philosophical bases of group methods. This confusion increases when distinctions are made only on process. When the philosophical bases are understood, certain distinctions become evident. In authoritarian group leadership the locus of evaluation is centered in the leader. In democratic leadership the locus of evaluation is in the group within the framework established by the leader. In group-centered leadership the locus of evaluation is in the group member. The principles of learning in the authoritarian approach are based chiefly on association psychology, in the democratic mode on field theory, and in group-centered leadership on self theory. The material within the authoritarian concept is selected and presented by the leader; in the democratic it may be selected and presented either by the leader or the group and confirmed by the leader; in the group-centered the material is selected and presented by the group member(s). Question, interpretation, analysis, suggestion, acceptance, reflection, approval, clarification, and evaluation constitute the responses of authoritarian and democratic leaderships. The group-centered leader- ship responses are acceptance, reflection, and clarification. Authoritarian group leaden rely upon their skill to diagnose, interpret, and explain. The democratic leader relies upon his ability to select those issues and problems for which he believes the members have the potentialities and his willingness to allow them to use these capacities. The group-centered leader relies on his ability to understand the meaning of the response from the member's frame of reference. He also depends on the member's urge toward health and potential ability to express his ideas and feelings. The training requirements of group leaders of different orientations are similar in many respects. Knowledge and skill are essential to each type of leadership. The authoritarian must believe in his ability to select, evaluate, and present material and to initiate action in relation to his decisions. The democratic leader must believe in the ability of the members to discuss and reach a solution or understanding concerning issues that he has selected or upon which he and the members agree. The group- centered leader must believe in the ability and motivation of the group member to select and evaluate material, to integrate ideas, and to initiate a higher quality of behavior. [ABSTRACT FROM AUTHOR]