Single-subject research (SSR) methodology is commonly associated with behavioral psychology, specifically applied behavior analysis, and is a research methodology [Page 1521]and intervention evaluation approach that is used by general and special educators, speech and language therapists, social workers, therapeutic recreation practitioners, clinical psychologists, and occupational therapists. Although used in basic and applied research, SSR methodology use in education and clinical practice has increased considerably in recent years as a means for objectively evaluating the effects of educational and treatment programs. In this age of accountability, SSR methodology is appropriate for use by professionals interested in the formative evaluation of their interventions.

SSR design, also referred to as single-case experimental design, N of 1 design, single N design, and quasiexperimental design, refers to ...