d_to_g function

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

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.

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.

Returns

• g: Unbiased Standardized mean difference statistic.

• var.g: Variance of g.

Author(s)

AC Del Re & William T. Hoyt

Maintainer: AC Del Re acdelre@gmail.com

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.