Cronbach's alpha

n. Cronbach's alpha is a gauge of the degree of reliability for multiple measures of a single construct. Similarly to the average correlation among items, Cronbach's alpha is used by researchers to determine the degree to which measures are accomplishing their objective, or the degree to which the measures hang together from a statistical standpoint. Cronbach's alpha is an indication of internal consistency, the degree to which items are measuring the same thing. Cronbach's alpha generally ranges from 0 to 1 but can occasionally yield values below 0 because of the way in which it is computed. Values closer to 1 indicate higher interitem consistency. There is no specific statistical test of significance for Cronbach's alpha. Instead, researchers make subjective interpretations of the value of Cronbach's alpha.      

- mwp