The importance of client-therapist-relationship in psychotherapy has often been stressed. On the one hand, the quality of this relationship has proved to be an important predictor of therapy outcome, on the other hand the relationship itself is realized as a complex dynamic pattern of interpersonal interaction. It seems appropriate to investigate this dynamics by a microprocess analysis with high resolution. Interactive plans (idiographic self-presentation unities) of client and therapist were coded by a sampling frequency of 10 seconds. The coding system of plan activation follows the idea of synchronous musical score notation of different orchestra instruments. It allows for the representation of contextualized interactive behaviors. The context is introduced by the consideration of synchronous and diachronous plan-activation patterns of the interaction partners.
The observed dynamic patterns are fulfilling the prerequisites of usual definitions of “chaos”: irregularity of the process, restricted prediction horizon, and still some global order of the dynamic process. Based on nominal data (on-off-patterns), a method for the identification of order within irregular patterns of plan activations is presented. The frequency distributions of plans realize the shape of 1/fα-noise, indicating features of self-organized criticality within the dynamic system of client-therapist-interaction.