Rorschach assessment of changes following psychotherapy: a meta-analytic review.

I examined Rorschach assessment of personality changes following psychotherapy. I conducted a comprehensive literature search to find all studies using the Rorschach method at least twice for the same participant in connection with psychotherapy. I conducted meta-analyses for 38 samples, and I performed regression analyses to identify moderating factors. Across all Rorschach scores, the total weighted sample effect size was r = .26, and nearly half the variables obtained effect sizes higher than .30. Several moderating factors were found. Most important, effect sizes increased with longer and more intensive therapy. More concern for interscorer reliability was associated with larger effect sizes, whereas a higher degree of scorer blinding was associated with smaller effect size magnitudes. Predicted levels of change based on the regression models indicated substantial increases in effect size with longer therapies. The data indicate that many elements in the Rorschach are valid indicators of change despite the poor reputation the method has acquired within psychotherapy research.