Within the framework of a brief review the state of the art of quality control for therapeutic work with special emphasis on interpersonal skills is summarized.The results of a documentation developed at the Medical School Hannover for ward sessions in psychiatry are presented. They are based on the evaluation of 190 ward sessions. For six months the behaviour of the patients as well as that of the therapists was measured by using a controlled rating scale. The results describe the characteristic differences between the therapists leading a ward-group with respect to the satisfaction with the session in relation to different kinds of quality models. The individual style of the therapists corresponding with the number of ward sessions performed proves to be an important factor for the quality of the therapy. The results are used for the design of a feedback system for the training of therapists.