Cronbach's alpha and McDonald's omega are widely used reliability or internal consistency measures in social, behavioral and education sciences. Alpha is reported in nearly every study that involves measuring a construct through multiple test items. The package 'coefficientalpha' calculates coefficient alpha and coefficient omega with missing data and nonnormal data. Robust standard errors and confidence intervals are also provided. A test is also available to test the tauequivalent and homogeneous assumptions. Since Version 0.5, the bootstrap confidence intervals were added.
Package details 


Author  Zhiyong Zhang and KeHai Yuan 
Maintainer  Zhiyong Zhang <johnnyzhz@gmail.com> 
License  GPL 
Version  0.7 
Package repository  View on CRAN 
Installation 
Install the latest version of this package by entering the following in R:

Any scripts or data that you put into this service are public.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.