A review of meta-analyses of single-subject experimental designs: Methodological issues and practice

Abstract

Several metrics have been suggested for summarizing results from single-subject experimental designs. This study briefly reviews the most commonly used metrics, noting their methodological limitations. This study also includes a synthesis of recent meta-analyses, describing which metrics were used and how meta-analysts handled dependence in the form of multiple treatments, outcomes, and participants per study. Guidelines for future methodological research and for single-subject experimental design meta-analysts are provided.

Source of funding: Preparation of this article was supported by a grant from the Institute of Education Sciences, U.S. Department of Education. However, the opinions expressed do not express the opinions of this agency.

Keywords:

• Meta–analysis
• effect sizes
• single–subject experimental–designs
• methodology

Notes

Source of funding: Preparation of this article was supported by a grant from the Institute of Education Sciences, U.S. Department of Education. However, the opinions expressed do not express the opinions of this agency.

¹All trends have been depicted, here, as positive. It is of course feasible that trends could be negative (reflecting a reduction in the behavioral outcome). The same conclusions apply for such scenarios.

²If residuals are negatively autocorrelated, then standard error estimates will be inflated with overly conservative Type I error rates.

References used in the narrative literature review are marked with an asterisk