ci.cronbach2: Confidence interval for a difference in Cronbach...

In statpsych: Statistical Methods for Psychologists

Confidence interval for a difference in Cronbach reliabilities in a 2-group design

Description

Computes a confidence interval for a difference in population Cronbach reliability coefficients in a 2-group design. The number of measurements (items, raters, forms) used in each group need not be equal.

For more details, see Section 2.15 of Bonett (2021, Volume 4)

Usage

ci.cronbach2(alpha, rel1, rel2, r1, r2, n1, n2)

Arguments

alpha	alpha level for 1-alpha confidence
rel1	estimated Cronbach reliability for group 1
rel2	estimated Cronbach reliability for group 2
r1	number of measurements used in group 1
r2	number of measurements used in group 2
n1	sample size for group 1
n2	sample size for group 2

Value

Returns a 1-row matrix. The columns are:

• Estimate - estimated reliability difference

• LL - lower limit of the confidence interval

• UL - upper limit of the confidence interval

References

\insertRef

Bonett2021statpsych

\insertRef

Bonett2015statpsych

Examples

ci.cronbach2(.05, .88, .76, 8, 8, 200, 250)

# Should return:
# Estimate     LL     UL
#     0.12 0.0697 0.1733
 

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