BootES: An R package for bootstrap confidence intervals on effect sizes

• Published in: Behavior research methods Vol. 45; no. 4; pp. 905 - 927
• Main Authors: Kirby, Kris N., Gerlanc, Daniel
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.12.2013; Springer Nature B.V
• Subjects: Appendix; Behavioral Science and Psychology; Cognitive Psychology; Confidence Intervals; Data Interpretation, Statistical; Estimates; Humans; Hypotheses; Mathematical Computing; Population; Programming Languages; Psychologists; Psychology; Sample Size; Software; Software Design; Task forces; Confidence intervals; R; Computer software; Effect size; Bootstrap; Resampling; Statistics
• ISSN: 1554-3528; 1554-351X; 1554-3528
• DOI: 10.3758/s13428-013-0330-5

Bootstrap Effect Sizes (bootES; Gerlanc & Kirby, 2012 ) is a free, open-source software package for R (R Development Core Team, 2012 ), which is a language and environment for statistical computing. BootES computes both unstandardized and standardized effect sizes (such as Cohen’s d , Hedges’s g , and Pearson’s r ) and makes easily available for the first time the computation of their bootstrap confidence intervals (CIs). In this article, we illustrate how to use bootES to find effect sizes for contrasts in between-subjects, within-subjects, and mixed factorial designs and to find bootstrap CIs for correlations and differences between correlations. An appendix gives a brief introduction to R that will allow readers to use bootES without having prior knowledge of R.