This paper describes a trajectory by which an individual achieves expertise in group psychotherapy. Five developmental stages are posited. In the decisional-anticipatory stage, interest is developed in group psychotherapy. In the trainee stage, the individual masters the knowledge base of group psychotherapy and obtains fledgling experiences in a group. In the novice stage, the individual obtains additional experience in running groups and becomes socialized into a community of group psychotherapists. In the proficiency stage, the individual narrows his or her group psychotherapy focus and obtains more specialized experience in that area. At this time, supervisory and consultation skills are often developed. In the final stage of expertise, the expert must engage in a process of recognizing its limits and must devise ways to maintain it. Research that focuses on one aspect of expertise, level of experience, is reviewed. Three dimensions of difference are identified: (a) complexity of conceptualization of members and interventions; (b) fostering openness and engagement; and (c) focusing on process.
