esc_mean_gain {esc}  R Documentation 
Compute effect size from Mean Gain Scores and Standard Deviations for prepost tests.
esc_mean_gain( pre1mean, pre1sd, post1mean, post1sd, grp1n, gain1mean, gain1sd, grp1r, pre2mean, pre2sd, post2mean, post2sd, grp2n, gain2mean, gain2sd, grp2r, r, es.type = c("d", "g", "or", "logit", "r", "f", "eta", "cox.or", "cox.log"), study = NULL )
pre1mean 
The mean of the first group at pretest. 
pre1sd 
The standard deviation of the first group at pretest. 
post1mean 
The mean of the first group at posttest. 
post1sd 
The standard deviation of the first group at posttest. 
grp1n 
The sample size of the first group. 
gain1mean 
The mean gain between pre and post of the first group. 
gain1sd 
The standard deviation gain between pre and post of the first group. 
grp1r 
The (estimated) correlation of prepost scores for the first group. 
pre2mean 
The mean of the second group at pretest. 
pre2sd 
The standard deviation of the second group at pretest. 
post2mean 
The mean of the second group at posttest. 
post2sd 
The standard deviation of the second group at posttest. 
grp2n 
The sample size of the second group. 
gain2mean 
The mean gain between pre and post of the second group. 
gain2sd 
The standard deviation gain between pre and post of the second group. 
grp2r 
The (estimated) correlation of prepost scores for the second group. 
r 
Correlation for withinsubject designs (paired samples, repeated measures). 
es.type 
Type of effect size that should be returned.

study 
Optional string with the study name. Using 
For this function, either the gain scores of mean and sd
(gain1mean
and gain1sd
for the first group and
gain2mean
and gain2sd
for the second group) must be
specified, or the prepost values (pre1mean
, post1mean
,
pre1sd
and post1sd
and the counterpart arguments for the
second group).
If the prepost standard deviations are available, no correlation value
grp1r
resp. grp2r
needs to be specified, because these can
then be computed based on tvalue computation. However, if grp1r
is specified, this value will be used (and no ttest performed).
The effect size es
, the standard error se
, the variance
of the effect size var
, the lower and upper confidence limits
ci.lo
and ci.hi
, the weight factor w
and the
total sample size totaln
.
If es.type = "r"
, Fisher's transformation for the effect size
r
and their confidence intervals are also returned.
Lipsey MW, Wilson DB. 2001. Practical metaanalysis. Thousand Oaks, Calif: Sage Publications
Wilson DB. 2016. Formulas Used by the "Practical MetaAnalysis Effect Size Calculator". Unpublished manuscript: George Mason University
# effect size of mean gain scores, with available prepost values esc_mean_gain(pre1mean = 13.07, pre1sd = 11.95, post1mean = 6.1, post1sd = 8.33, grp1n = 78, pre2mean = 10.77, pre2sd = 10.73, post2mean = 8.83, post2sd = 9.67, grp2n = 83) # same as above, but with assumed correlation of .5 # Note that effect size is the same, but variance differs esc_mean_gain(pre1mean = 13.07, pre1sd = 11.95, post1mean = 6.1, grp1r = .5, post1sd = 8.33, grp1n = 78, pre2mean = 10.77, pre2sd = 10.73, post2mean = 8.83, post2sd = 9.67, grp2n = 83, grp2r = .5) # effect size based on gain scores for mean and sd. note that the # prepost correlations must be given esc_mean_gain(gain1mean = 1.5, gain1sd = 1, grp1n = 40, grp1r = .5, gain2mean = .7, gain2sd = .8, grp2n = 50, grp2r = .5)