Several functions are available for calculating the most
widely used effect sizes (ES), along with their variances, confidence
intervals and p-values. The output includes ES's of d (mean difference), g
(unbiased estimate of d), r (correlation coefficient), z' (Fisher's z), and
OR (odds ratio and log odds ratio). In addition, NNT (number needed to
treat), U3, CLES (Common Language Effect Size) and Cliff's Delta are
computed. This package uses recommended formulas as described in The
Handbook of Research Synthesis and Meta-Analysis (Cooper, Hedges, &
Valentine, 2009).