Cronbach's Alpha
- 1 file
- 5 downloads
Computes standardized and unstandardized Cronbach's alphas for an nR x nI array of nR repetitions of observations of nI items. Cronbach's alpha measures the reliability of psychometric test scores.
A couple other versions of functions for calculating Cronbach's alpha exist on the exchange but are not well documented. Leontitsis' calculates only unstandardized alphas and Nagel's calculates standardized scores but uses Spearman correlation instead of Pearson.
This function calculates both and uses Pearson correlations.
Cite As
Alex Schlegel (2020). Cronbach's Alpha (https://www.mathworks.com/matlabcentral/fileexchange/38320-cronbach-s-alpha), MATLAB Central File Exchange. Retrieved .
Comments and Ratings (5)
MATLAB Release Compatibility
Platform Compatibility
Windows macOS LinuxTags
Discover Live Editor
Create scripts with code, output, and formatted text in a single executable document.
Select a Web Site
Choose a web site to get translated content where available and see local events and offers. Based on your location, we recommend that you select: .
Select web siteYou can also select a web site from the following list:
Americas
- América Latina (Español)
- Canada (English)
- United States (English)
Europe
- Belgium (English)
- Denmark (English)
- Deutschland (Deutsch)
- España (Español)
- Finland (English)
- France (Français)
- Ireland (English)
- Italia (Italiano)
- Luxembourg (English)
- Netherlands (English)
- Norway (English)
- Österreich (Deutsch)
- Portugal (English)
- Sweden (English)
- Switzerland
- United Kingdom (English)
Dominik Mattioli (view profile)
Should include nanmean, corrcoef(..., 'rows', 'complete'), and cov(..., 'omitrows') in order to accomodate inputs with NaN values.
Dominik Mattioli (view profile)
Kirsten (view profile)
Alex Schlegel (view profile)
Hi Ben, I am not sure, but I just used the formula from the Wikipedia article on Cronbach's alpha, which looks like it derives from eq. 44 of the original paper (doi:10.1007/bf02310555). That equation appears to refer to straight means of correlations, rather than using Fisher z-transforms.
Ben (view profile)
Thanks for the function!
Small comment: When calculating the mean of correlations, shouldn't one use Fisher z-transformed values and then transform back? So, tanh(mean(atanh(r))) instead of mean(r)?