Preprint has been published in a journal as an article
DOI of the published article 10.7717/peerj.10314
Preprint / Version 1

Does One Effect Size Fit All? The Case Against Default Effect Sizes for Sport and Exercise Science


  • Aaron Caldwell
  • Andrew Vigotsky



applied statistics, exercise, kinesiology, physiology, sport, statistics


Recent discussions in the sport and exercise science community have focused on the appropriate use and reporting of effect sizes. Sport and exercise scientists often analyze repeated-measures data, from which mean differences are reported. To aid the interpretation of these data, standardized mean differences (SMD) are commonly reported as description of effect size. In this manuscript, we hope to alleviate some confusion. First, we provide a philosophical framework for conceptualizing SMDs; that is, by dichotomizing them into two groups: magnitude-based and signal-to-noise based SMDs. Second, we describe the statistical properties of SMDs and their implications. Finally, we provide high-level recommendations for how sport and exercise scientists can thoughtfully report raw effect sizes, SMDs, or other effect sizes for their own studies. This conceptual framework provides sport and exercise scientists with the background necessary to make and justify their choice of an SMD. The code to reproduce all analyses and figures within the manuscript can be found at the following link:


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