Coefficient Alpha, which is widely used in empirical research, estimates the reliability of a test consisting of parallel items. In practice it is difficult to compare values of alpha across studies as it depends on the number of items used. In this paper we provide a simple solution, which amounts to computing the confidence intervals of an alpha, as these intervals automatically account for differences across the numbers of items. We also give appropriate statistics to test for significant differences of alpha values across studies.

Additional Metadata
Keywords Cronbach's alpha, confidence intervals, test reliability
JEL Econometric and Statistical Methods: Other (jel C19), Statistical Decision Theory; Operations Research (jel C44), Business Administration and Business Economics; Marketing; Accounting (jel M), Marketing (jel M31)
Persistent URL
Series ERIM Report Series Research in Management
Koning, A.J, & Franses, Ph.H.B.F. (2003). Confidence Intervals for Cronbach's Coefficient Alpha Values (No. ERS-2003-041-MKT). ERIM Report Series Research in Management. Retrieved from