Single-participant research design - Bringing science to managed care

The ongoing transition to managed health care continues to have repercussio ns for health care providers, perhaps the most important of which is an emp hasis on accountability for demonstrating the usefulness of clinical interv entions. This requirement places a premium on intervention research and hig hlights the historically strained relationship between psychological resear ch and professional practice. In the midst of this challenge, researchers h ave increasingly criticized the logic and practice of traditional null hypo thesis significance testing. This article describes the history, epistemolo gy, and advantages of single-participant research designs for behavioral sc ientists and professionals in clinical settings. Although its lack of corre spondence with the Fisherian tradition has precluded widespread adoption, t he single-participant alternative features a design power and flexibility w ell suite to both basic science and applied research.