An empirical analysis of alleged misunderstandings of coefficient alpha

Abstract

Cronbach’s alpha is the most frequently used measure to investigate the reliability of measurement instruments. Despite its frequent use, many warn for misinterpretations of alpha. These claims about regular misunderstandings, however, are not based on empirical data. To understand how common such beliefs are, we conducted a survey study to test researchers’ knowledge of and beliefs about alpha. For this survey, we selected authors from recent papers, in which alpha was used. The results provide empirical evidence for the claims that researchers have difficulty interpreting alpha in a proper way. At the same time, we expounded the claims, by showing that whereas some beliefs are fairly typical, others are not so often seen. This non-technical paper, aimed at both statisticians and substantive researchers, is concluded by providing a few suggestions that could be helpful to get us out of the current stalemate regarding the usability of alpha and its alternatives.