Classification of variables in psychotherapy research: Therapeutic change and the concept of artifact

Conceptualizes change in therapeutic process and outcome in terms of the operation of both primary and secondary variables of influence. Secondary variables (e.g., enthusiasm of the therapist) are distinguishable from primary variables (e.g., treatment technique) in their historical development, the amount of data supporting them, and their character as subtle variables of influence. The formation of secondary factors can be aligned usefully with the development of the concept of artifact to aid in the classification of therapeutic variables. Classification of this kind draws attention to the operation of specific functional effects that should not be viewed, however, in an exhaustive or causal way. (86 ref)