Examination of the Biasing Properties of Cronbach Coefficient Alpha under Conditions of Varying Shapes of Data Distribution: A Monte Carlo Simulation

The biasing properties of Cronbach alpha in fixed-format tests were examined in a Monte Carlo simulation under conditions of varying shapes of data distribution. The distributions of data examined were normal (3, 1), uniform (1, 5), skewness biased, Kurtosis biased (leptokurtic), and U-shaped. Analysis indicated that alpha was significantly different from zero under the normal and uniform distributions; however, negative interitem correlations and marginal SDs might have been responsible for that effect. The magnitude of alpha was negligible so it is suggested that researchers can use alpha with data having various distributional properties.