Reliability Analysis

"Once the factor analysis has done its job of organizing items into groups, it is time to see how well the groups of items hold together. This is the job of reliability analysis. Although there are many different reliability statistics, the most commonly used is the Cronbach’s alpha. The Cronbach’s alpha (with a Greek symbol of α) uses the associations among a set of items to indicate how well the items, as a group, hold together. Conceptually, the idea is that all of the survey items that are supposed to measure a single underlying construct should be answered in a similar way by respondents."