hedgesG: Hedges' g Effect Size with Pooled Standard Deviation

In imt: Impact Measurement Toolkit

Hedges' g Effect Size with Pooled Standard Deviation

Description

Calculates Hedges' g, a standardized effect size for comparing means. This version includes a small-sample correction factor (omega) and uses the pooled standard deviation.

Usage

hedgesG(n_t, n_c, y_t, y_c, s_t, s_c)

Arguments

n_t	Numeric value representing the sample size of the treatment group.
n_c	Numeric value representing the sample size of the control group.
y_t	Numeric value representing the mean of the treatment group.
y_c	Numeric value representing the mean of the control group.
s_t	Numeric value representing the standard deviation of the treatment group.
s_c	Numeric value representing the standard deviation of the control group.

Details

Hedges' g is a variation of Cohen's d that adjusts for small-sample bias. It is calculated as the difference in means divided by the pooled standard deviation, then multiplied by a correction factor.

Value

The calculated Hedges' g effect size.

References

Hedges, L. V. (1981). Distribution theory for Glass's estimator of effect size and related estimators. Journal of Educational Statistics, 6(2), 107-128.

imt documentation built on Sept. 11, 2024, 5:41 p.m.