Contribution of therapists to patients' experiences in psychotherapy: A components of variance model for analyzing process data

One goal in the investigation of therapeutic process is the determination of the kinds of patients or therapists that have certain experiences in psychotherapy. A logical prerequisite would be that the selected process variables have a substantial part of their variance that is attributable to individual differences among participants. This article presents a description of an analysis of variance components model for estimating proportions of variance in process measures and illustrates this model by applying it to reports of 108 18-52 yr old patients' experiences in psychotherapeutic sessions to describe the extent to which these experiences are a function of differences among therapists.