ci.reliability: Confidence interval for a reliability coefficient

In statpsych: Statistical Methods for Psychologists

Confidence interval for a reliability coefficient

Description

Computes a confidence interval for a population reliability coefficient such as Cronbach's alpha or McDonald's omega using an estimate of the reliability and its standard error. The standard error can be a robust standard error or bootstrap standard error obtained from an SEM program. Use ci.cronbach for Cronbach's alpha if parallel measurements can be assumed.

Usage

ci.reliability(alpha, rel, se, n)

Arguments

alpha	alpha level for 1-alpha confidence
rel	estimated reliability
se	standard error of reliability
n	sample size

Value

Returns a 1-row matrix. The columns are:

• Estimate - estimated reliability (from input)

• LL - lower limit of the confidence interval

• UL - upper limit of the confidence interval

Examples

ci.reliability(.05, .88, .0147, 100)

# Should return:
# Estimate         LL        UL
#     0.88  0.8489612 0.9065575
 

statpsych documentation built on June 10, 2025, 5:11 p.m.