COMPARATIVE SINGLE-SUBJECT RESEARCH - DESCRIPTION OF DESIGNS AND DISCUSSION OF PROBLEMS

This article describes four single-subject research designs used to make comparisons between two or more interventions (independent variables). These include the multitreatment design, alternating treatments design, adapted alternating treatments design, and parallel treatments design. Three problems faced in using these designs are described: multitreatment interference, the nonreversibility of some socially important behaviors, and the need to separate the effects of each treatment. The ways in which these research designs address the problems inherent in comparative research are discussed, as are issues related to conducting comparative research.