Statistics Notes: Numerical Examples of Cronbach's Alpha

Cronbach's alpha is easy to use to measure consistency of responses. For an example, we may have two variables that should measure the same thing; therefore, those two variables should be correlated. In medical, we can use two variables---ability to walk and ability to climb stairs---to measure impairment of patients having cervical myelopathy. Theoretically, we understand that the impairment will equally affect the both ability to walk and to climb. Thus, we expect a high Cronbach's alpha for the both variables. Full article: Cronbach's Alpha.