Advantages of the ordinal alpha from Cronbach's illustrated with the who-AUDIT survey
Overview
Objectives: Explain the advantages of the use of the ordinal Alpha for situations in which the Cronbach's assumptions are not fulfilled and show the usefulness of the ordinal Alpha with the Chilean version of the AUDIT, as well as provide the commands in the R programming language for the relevant calculations.
Methods: Cronbach's and the ordinal Alpha in the case of the AUDIT questionnaire applied to 419 a Chilean University students were compared.
Results: In all domains, the ordinal Alpha proved to be greater than the Cronbach alpha, which is consistent with that found in the literature. Considering the ordinal Alpha accepted the reliability of each of the domains and the complete survey, which does not occur completely when working with Cronbach's.
Conclusions: To make decisions about the reliability of a dimension you should consider an index that meets the necessary for use cases, since failure to do so can lead to erroneous conclusions and affect significantly the development of a research . The values of the alpha of Cronbach underestimate the reliability of an instrument when working with ordinal scales.