size.ci.cronbach: Sample size for a Cronbach reliability confidence interval

In statpsych: Statistical Methods for Psychologists

Sample size for a Cronbach reliability confidence interval

Description

Computes the sample size required to estimate a Cronbach reliability with desired confidence interval precision. Set the reliability planning value to the smallest value within a plausible range for a conservatively large sample size.

Usage

size.ci.cronbach(alpha, rel, r, w)

Arguments

alpha	alpha value for 1-alpha confidence
rel	reliability planning value
r	number of measurements (items, raters, forms)
w	desired confidence interval width

Details

For more details, see Section 4.26 of Bonett (2021, Volume 1)

Value

Returns the required sample size

References

\insertRef

Bonett2015statpsych

\insertRef

Bonett2021statpsych

Examples

size.ci.cronbach(.05, .75, 5, .15)

# Should return:
# Sample size
#         109
 

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