A Test of the Hypothesis that Cronbach's Alpha or Kuder-Richardson Coefficent Twenty is the Same for Two Tests

Abstract

An approximate statistical test is derived for the hypothesis that the reliability coefficients (Cronbach's α ) associated with two measurement procedures are equal. Control of Type I error is investigated by comparing empirical sampling distributions of the test statistic with the theoretical model derived for it. The effect of platykurtosis in the test-score distribution on the test statistic is also considered.