The task for supervision is to create a setting in which the capacity to learn can develop. To provide conditions in which learning can develop is not easy and can be complicated by the trainee or by the supervisor; dynamic factors and inherent ambiguities in the supervisory situation frequently stimulate conflicts and influence the learning and teaching process. On the one hand, the supervisor can be experienced as a mentor, someone to relate to, rely upon and identify with, and on the other hand he can be a expected to be a judge, controlling in the interests of the body of professionals and a delegate of the institution. In a study of the learning process, analysing transcripts of supervisory sessions, it was demonstrated that learning occured frequently when the supervisor was keeping a continuous and stable focus on the trainee's reconstruction of his interaction with the patient, viewing the trainee-patient interaction as a ''system'' with its own boundaries and frame. Boundaries around the interaction between trainee and supervisor have to be maintained by the supervisor through a continuous attention on keeping to the primary task, helping the trainee to comprehend the system of interaction with his patient.