alpha {coefficientalpha}

Robust Cronbach's alpha and McDonald's omega

Description

Calculate alpha or omega for a given data set.

Usage

alpha(y, varphi = 0.1, se = FALSE, test = TRUE, 
complete =FALSE, auxiliary = NULL, drop, silent = TRUE)
omega(y, varphi = 0.1, se = FALSE, test = TRUE, 
complete =FALSE, auxiliary = NULL, drop, silent = TRUE)

Arguments

y

Data

varphi

Downweight rate

se

Whether to estimate standard error. It might take significant more time if se is requested with many items.

test

Whether to test the assumption of alpha (tau equivalent test) or omega (homogeneous test).

complete

Calculate alpha/omega only based on complete data (listwise deletion)

auxiliary

Provide a matrix or data frame of auxiliary variables for missing data analysis.

drop

The row number of cases to be dropped from the analysis.

silent

Whether to print information of the analysis.

Author(s)

Zhiyong Zhang and Ke-Hai Yuan

References

Zhang, Z. & Yuan, K.-H. (2014). Robust Coefficients Alpha and Omega and their Confidence Intervals: Methods and Software.

Examples

data(example)

alpha(example, varphi=.01)
omega(example, varphi=.01)