SINGLE-CASE STUDIES - CHANGING-CRITERION DESIGN AND ALTERNATING DESIGN

The primary focus of this article is on delineating and explaining the essential characteristics of single-case research methodology applied within the domain of psychotherapy research. Single-case research is presented as a subclass of intrasubject research, and separate terms f or three different basic types will be proposed. Two designs, the chan ging-criterion and the alternating design, will be explained through r esearch examples. The goal is to create greater clarity about single-c ase designs and thus facilitate a discussion of the potential and limi tations of such research by studying the psychotherapy change process and to promote their application.