Asay, T., & Lambert, M. (1999). The Empirical Case For The Common Factors In Therapy: Quantitative findings. American Psychological Association.
Abstract: The authors begin with a brief survey of the quantitative evidence establishing the effectiveness of therapy. From there, they turn their attention to the 4 principal common factors accounting for improvement in therapy: client/extra therapeutic, relationship, placebo, hope and expectancy, and models/techniques. Research supporting the contribution of each of these factors is sampled and major findings highlighted. Drawing on the results from psychotherapy outcome research and particularly the literature on the common factors, the authors conclude their chapter with a list of recommendations for clinical practice. (PsychINFO Database Record © 2015 APA, all rights reserved)