Creating comparability among reliability coefficients: the case of Cronbach alpha and Cohen kappa.
Cronbach alpha and Cohen kappa were compared and found to differ along two major facets. A fourfold classification system based on these facets clarifies the double contrast and produces a common metric allowing direct comparability. A new estimator, coefficient beta, is introduced in the process and is presented as a complement to coefficient alpha in estimating the psychometric properties of test scores and ratings.
Becker
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Department of Psychology, University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba, Canada R3B 2E9. psychology@io.uwinnipeg.ca
D006801:Humans; D008432:Mathematical Computing; D011581:Psychological Tests / Q000706:statistics & numerical data*; D011594:Psychometrics; D015203:Reproducibility of Results