Single-case experimental designs in medical education: an innovative research method

This paper presents an argument for more extensive use of single-case experimental research designs in medical education research. Single-case experimental designs consist of a group of experimental techniques that are widely used in the social sciences but are just beginning to be utilized by medical researchers. The method emphasizes reliable observations of behavior, repeated measurements of outcome, and individualized tailoring of objectives for each subject; all of these occur within a system that allows an experimental analysis to be conducted. Single-case designs are particularly useful when only small numbers of participants are available for a relatively long period of time. Trends in medical education toward individualized instruction, adult-centered learning, and fine-grained analyses of medical skills and knowledge make this field especially amenable to single-case experimental designs. Issues of internal and external validity, generality, practicality, and ethics are discussed, and several typical designs are illustrated. While the emergence of qualitative research methods in medical education may prove useful, single-case designs can maintain experimental science's emphasis on methodologic rigor, while allowing the flexibility often needed to conduct research in applied settings.