Single-Case Design in Psychophysiological Research. Part I: Context, Structure, and Techniques


  • Scott A. Gustafson
  • Stephanie L. Nassar
  • Dwight E. Waddell



There is a growing consensus in the clinical literature about the importance of establishing and utilizing empirically supported treatments (ESTs). A number of established criteria for determining the efficacy and effectiveness levels of treatments are reviewed, and an argument is put forth that the research paradigm of large-scale group comparison designs may not be the best conceptual fit for studying psychophysiological phenomena. Clinical psychophysiology employs reinforcing successive approximations of functional abilities: a model closer in nature to operant conditioning, physical rehabilitation, and education than the standard pharmacological model. Single-case designs have a long, well-accepted history in scientific disciplines and require resources that allow practice-level clinicians to make meaningful contributions to the scientific literature. They also have a clear role in the establishment of a treatment as an EST. A discussion of the logic, structure, and techniques of single-case design is presented in sufficient detail to actively construct publishable studies. The adaptive nature of this technique makes it possible to address a wide range of potential psychophysiological research questions, along with barriers to utilization, including ethical considerations. Techniques are presented to allow researchers to examine treatment efficacy and effectiveness as well as isolate components of treatment to determine the most powerful elements of a clinical intervention.