A Meta-Analysis of Cronbach's Coefficient Alpha

Despite some limitations, Cronbach's coefficient alpha remains the most widely used measure of scale reliability. The purpose of this article was to empirically document the magnitudes of alpha coefficients obtained in behavioral research, compare these obtained values with guidelines and recommendations set forth by individuals such as Nunnally (1967, 1978), and provide insights into research design characteristics that may influence the size of coefficient alpha. Average reported alpha coefficients ranged from .70 for values and beliefs to .82 for job satisfaction. With few exceptions, there were no substantive relationships between the magnitude of coefficient alpha and the research design characteristics investigated. Copyright 1994 by the University of Chicago.