Converts a t-test value to an effect size of d (mean difference), g (unbiased estimate of d), r (correlation coefficient), z (Fisher's z), and log odds ratio. The variances of these estimates are also computed.
Usage
tt_to_es(t, n.1, n.2)
Arguments
t
t-test value reported in primary study.
n.1
Sample size of treatment group.
n.2
Sample size of comparison group.
Value
dStandardized mean difference (d).
var.dVariance of d.
gUnbiased estimate of d.
var.gVariance of g.
rCorrelation coefficient.
var.rVariance of r.
log_oddsLog odds ratio.
var.log_oddsVariance of log odds ratio.
nTotal sample size.
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.