The connection assumed in the "Generic Model of Psychotherapy" of Orlinsky and Howard (1986) between therapeutic interventions and the openness of the client, on one hand, and the short and long-term therapeutic outcome, on the other hand, is tested. Three different treatment conditions, namely, interactional behavior therapy, broad-spectrum-behavior therapy, and client-centered therapy were compared in a controlled study with reference to the relation between these variables. The results confirm the central role of the client's openness in the therapy process, but also show the connection assumed in the Generic Model is not equally present in all therapy forms.