Impact of Within-Case Variability on Tau-U and Regression-Based Effect Size Measures for Single-Case Experimental Data

• In Event: Hilton Roundtable Session 1
  In Roundtable Session: Methodological Advances in Experimental Design

Abstract

The influence of within-case variance on single case design effect size measures remains unexplored. In this study, we demonstrate the impact of the magnitude of the within-case variability on the Tau-U variants and the regression-based effect size. Data was simulated for 36 different conditions, and each condition was replicated 10 times. Results demonstrate that the magnitude of the within-case variance influences the Tau-U measures, but the within-case variance does not systematically influence the regression-based effect size measure. We encourage researchers to visually analyze graphs and to then use appropriate guidelines for interpretation. We also encourage researchers to report multiple effect size measures when doing single case research to see if consistent results are obtained across measures.

Authors

• Joelle Fingerhut, Rutgers University

• Xinyun Xu, University at Albany-State University of New York

• Mariola Moeyaert, University at Albany