size.ci.cronbach2: Sample size for a 2-group Cronbach reliability difference...

In statpsych: Statistical Methods for Psychologists

Sample size for a 2-group Cronbach reliability difference confidence interval

Description

Computes the sample size per group (assuming equal sample sizes) required to estimate a difference in population Cronbach reliability coefficients with desired precision in a 2-group design.

Usage

size.ci.cronbach2(alpha, rel1, rel2, r, w)

Arguments

alpha	alpha level for hypothesis test
rel1	reliability planning value for group 1
rel2	reliability planning value for group 2
r	number of measurements (items, raters, forms)
w	desired confidence interval width

Details

For more details, see Section 2.19 of Bonett (2021, Volume 4)

Value

Returns the required sample size for each group

References

\insertRef

Bonett2015statpsych

\insertRef

Bonett2021statpsych

Examples

size.ci.cronbach2(.05, .85, .70, 8, .15)

# Should return:
# Sample size per group
#                   180
 

statpsych documentation built on Jan. 13, 2026, 1:07 a.m.