Confidence interval for a subgroup difference in average Cronbach reliabilities
Source:R/meta_comp.R
meta.sub.cronbach.Rd
Computes the estimate, standard error, and confidence interval for a difference in average Cronbach reliability coefficients for two mutually exclusive subgroups of studies. Each set can have one or more studies. The number of measurements used to compute the sample reliablity coefficient is assumed to be the same for all studies.
Value
Returns a matrix with three rows:
Row 1 - estimate for Set A
Row 2 - estimate for Set B
Row 3 - estimate for difference, Set A - Set B
The columns are:
Estimate - estimated average correlation or difference
SE - standard error
LL - lower limit of the confidence interval
UL - upper limit of the confidence interval
References
Bonett DG (2010). “Varying coefficient meta-analytic methods for alpha reliability.” Psychological Methods, 15(4), 368–385. ISSN 1939-1463, doi:10.1037/a0020142 . Bonett DG, Wright TA (2015). “Cronbach's alpha reliability: Interval estimation, hypothesis testing, and sample size planning.” Journal of Organizational Behavior, 36(1), 3–15. ISSN 08943796, doi:10.1002/job.1960 .
Examples
n <- c(120, 170, 150, 135)
rel <- c(.89, .87, .73, .71)
group <- c(1, 1, 2, 2)
r <- 10
meta.sub.cronbach(.05, n, rel, r, group)
#> Estimate SE LL UL
#> Set A: 0.88 0.01068845 0.8581268 0.8999386
#> Set B: 0.72 0.02515130 0.6684484 0.7668524
#> Set A - Set B: 0.16 0.02732821 0.1082933 0.2152731
# Should return:
# Estimate SE LL UL
# Set A: 0.88 0.01068845 0.8581268 0.8999386
# Set B: 0.72 0.02515130 0.6684484 0.7668524
# Set A - Set B: 0.16 0.02732821 0.1082933 0.2152731