One of the main goals in the Norwegian government plan to improve mental healthcare was to improve client's impact on their own treatment. A Report from the department of health shows that clients do not feel that this goal is reached. To make changes in therapy, one of the most important factors is the client himself. Klient- og resultatstyrt praksis is developed to put the client in front and utilize his own theory of change in therapy. This paper investigates the effect common factors has in therapy, and how KOR helps the therapist utilize important factors for change. KOR has been implemented in several clinics and shows good results. This paper investigates the development and research on KOR and tries to give a picture of its validity. Research on expertise shows that one of the most important elements to get better is feedback. KOR is a method that can help therapists to get better thru the utilization of key elements in expertise. The preliminary results on KOR research are impressive and it might be that the time is right for therapists to start using feedback in therapy.