is_specified_input_of
effect size estimate
confidence interval calculation
Hedges's g
Alejandra Gonzalez-Beltran
Hedges's g is an estimator of effect size, which is similar to Cohen's d and is a measure based on a standardized difference. However, the denominator, corresponding to a pooled standard deviation, is computed differently from Cohen's d coefficient, by applying a correction factor (which involves a Gamma function).
Orlaith Burke
Philippe Rocca-Serra
adapted from :
http://en.wikipedia.org/wiki/Effect_size#Cohen.27s_d
and
http://blog.stata.com/tag/cohens-d/
pending final vetting