Single-Case Experimental Designs: Clinical Research and Practice

In recent decades, it has become clear that data collected at an individual level provides critical evidence that can be used to refine theories, improve treatment, and inform health care decisions. Recent developments in the field of single-case experimental design (SCED) have provided new opportunities to utilize data from a single person. After a brief historical background to why and how SCED recently remerged, this chapter provides a state-of-the art overview of key aspects of SCED methodology. It provides a description of the most frequently used SCEDs, including phase designs, multiple-baseline designs, changing criterion designs, and alternating treatment designs. The chapter then provides an overview of the methods that can be applied to analyze single-case data. Visual analysis and effect size metrics, as well as inferential statistics for single-case data are described and illustrated. The chapter subsequently discusses the role that standards play in the design of SCED research and research synthesis, including examples of existing guidelines. Finally, the chapter discusses some future directions that may help to move the field forward.