Testing hypotheses involving Cronbach's alpha using marginal models
Kuijpers,R.E. van der Ark,L.A. Croon,M.A.
Kuijpers,R.E.
van der Ark,L.A.
Croon,M.A.
Abstract
We discuss the statistical testing of three relevant hypotheses involving Cronbach's alpha: one where alpha equals a particular criterion; a second testing the equality of two alpha coefficients for independent samples; and a third testing the equality of two alpha coefficients for dependent samples. For each of these hypotheses, various statistical tests have been proposed. Over the years, these tests have depended on progressively fewer assumptions. We propose a new approach to testing the three hypotheses that relies on even fewer assumptions, is especially suited for discrete item scores, and can be applied easily to tests containing large numbers of items. The new approach uses marginal modelling. We compared the Type I error rate and the power of the marginal modelling approach to several of the available tests in a simulation study using realistic conditions. We found that the marginal modelling approach had the most accurate Type I error rates, whereas the power was similar across the statistical tests.
Description
Date
2013
Journal Title
Journal ISSN
Volume Title
Publisher
Research Projects
Organizational Units
Journal Issue
Keywords
Citation
Kuijpers, R E, van der Ark, L A & Croon, M A 2013, 'Testing hypotheses involving Cronbach's alpha using marginal models', British Journal of Mathematical and Statistical Psychology, vol. 66, no. 3, pp. 503-520. https://doi.org/10.1111/bmsp.12010