Exploratory Factor Analysis with SAS

Factors That Influence Alpha and Its Use

Although alpha is generally the preferred method of estimating reliability (particularly in the social sciences), it is a fairly basic method that can be easily influenced. It is not robust with respect to many potential characteristics of a sample or instrument. It is important to be aware of these characteristics so that appropriate steps can be taken to reduce their effect and improve our estimates of reliability. Each characteristic is described below.

High average inter-item correlation. All other things being equal, alpha is higher when the average correlation between items is higher. But even Cronbach specifically pointed out that when inter-item correlations are low, alpha can be high with enough ...