Law and Human Behavior

, Volume 29, Issue 5, pp 615–620 | Cite as

Comparing Effect Sizes in Follow-Up Studies: ROC Area, Cohen's d, and r

  • Marnie E. Rice
  • Grant T. Harris


In order to facilitate comparisons across follow-up studies that have used different measures of effect size, we provide a table of effect size equivalencies for the three most common measures: ROC area (AUC), Cohen's d, and r. We outline why AUC is the preferred measure of predictive or diagnostic accuracy in forensic psychology or psychiatry, and we urge researchers and practitioners to use numbers rather than verbal labels to characterize effect sizes.

Key Words

effect size ROC area risk assessment predictive accuracy 


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Copyright information

© American Psychology-Law Society/Division 41 of the American Psychological Association 2005

Authors and Affiliations

  1. 1.Mental Health CentrePenetanguisheneCanada

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