In recent years, there has been an increasing focus in psychotherapy research toward identifying combinations of patient and treatment factors that increase treatment effectiveness (butler, 1991;Blatt & Felsen, 1993; Dance & Neufeld, 1988). As indicated by an examination of attributetreatment interactions conducted previously in educational testing research (Cronbach & Snow, 1977), such study requires sophistication in research Reprinted from the J o u d of Consulting and Clinical Psychology, 63, 296-307. (1995).