Single-case designs

Single-case designs (also called single-case experimental designs) are system of research design strategies that can provide strong evidence of intervention effectiveness by using repeated measurement to establish each participant (or case) as his or her own control. The flexibility of the designs, and the focus on the individual as the unit of measurement, has led to an increased interest in the use of single-case design research in many areas of intervention research. The purpose of this chapter is to introduce the reader to the basic logic underlying the conduct and analysis of single-case design research by describing the fundamental features of this type of research, providing examples of several commonly used designs, and reviewing the guidelines for the visual analysis of single-case study data. Additionally, current areas of consensus and disagreement in the field of single-case design research will be discussed.