Abstract

A scheme is proposed for determining when a psychological treatment for a specific problem or disorder may be considered to be established in efficacy or to be possibly efficacious. The importance of independent replication before a treatment is established in efficacy is emphasized, and a number of factors are elaborated that should be weighed in evaluating whether studies supporting a treatment's efficacy are sound. It is suggested that, in evaluating the benefits of a given treatment, the greatest weight should be given to efficacy trials but that these trials should be followed by research on effectiveness in clinical settings and with various populations and by cost-effectiveness research.