Assessing clinical significance: proposed extensions to method.

Jacobson, Follette, and Revenstorf's (1984) proposal for assessing clinical significance provides a needed convention for psychotherapy outcome research. Several limitations that exists in this method (Jacobson & Revenstorf, 1988) are addressed in this paper and extensions are proposed. Specifically, limitations regarding the operationalization of the underlying social validation methodology in the derivation of normative samples and the resultant standards they set are discussed. Extensions and guidelines are proposed for specifying normative samples, determining the distinctness of these samples, and expanding procedures to accommodate multiple samples. This paper initially assumes a psychometric perspective and presents extensions, based on the Symptom Checklist 90-R. Then it shifts to a clinician perspective and applies reliable change estimates and cutoff scores to actual outcome data by analyzing the progress of four patients during and after therapy. The overall merit and utility of extensions to clinical significance are then discussed.