es.d: Cohen d effect size calculation for one or two means
Description
This function takes as inputs a difference between two means and a standard deviation
and outputs the d effect size as defined by Cohen (1988),
also called the standardized mean difference.
Usage
es.d(delta = NULL, sd = 1)
Value
A list of the arguments and the d effect size.
Arguments
delta
If one mean: muA (the true mean) - mu0 (the mean under the null). If two means: DeltaA (the true difference mu1 - mu2) - Delta0 (the difference under the null).
sd
The estimated standard deviation; defaults to 1.
Details
Cohen J (1988) Statistical Power Analysis for the Behavioral Sciences, 2nd edition.
Lawrence Erlbaum Associates, Hillsdale, New Jersey