Evaluating Intervention Effects in Single‐Case Research Designs

Single‐case research designs have primarily relied on visual analysis for determining treatment effects. However, current foci on evidence‐based treatment have given rise to the development of new methods. This article presents descriptions, calculations, strengths and weaknesses, and interpretative guidelines for 5 effect size indices: the percent of nonoverlapping data, the percent of data exceeding the median, improvement rate difference, nonoverlap of all pairs, and Tau‐U.