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MAc (version 1.1.1)

d_to_g: Standardized Mean Difference (d) Statistic to Unbiased Standardized Mean Difference (g)

Description

Eliminates the small upward bias of d to provide an unbiased estimate of the population effect size parameter (g). This procedure will compute g for a single value of d.

Usage

d_to_g(d, var.d, n.1, n.2)

Arguments

d

Standardized mean difference statistic (d has a slight bias).

var.d

Variance of d.

n.1

Sample size of treatment group.

n.2

Sample size of comparison group.

Value

g

Unbiased Standardized mean difference statistic.

var.g

Variance of g.

References

Borenstein (2009). Effect sizes for continuous data. In H. Cooper, L. V. Hedges, & J. C. Valentine (Eds.), The handbook of research synthesis and meta analysis (pp. 279-293). New York: Russell Sage Foundation.