Statistics

the Cronbach Alpha coefficient, defined by the following relation: 

where K defines number of items (Data columns) and sigma(i,j) estimated covariance between item i and j.

Cronbach's Alpha measures how well a set of items (or variables) measures a single unidimensional latent construct. When data have a multidimensional structure, Cronbach's Alpha will usually be low. Technically speaking, Cronbach's Alpha is not a statistical test - it is a coefficient of reliability (or consistency).

Functions