Σύγκριση μεθόδων

	Πολυτομική Ωμέγα του McDonald	Ανάλυση Ορθολογικής Αξιοπιστίας
Πεδίο	Ψυχομετρία	Ψυχομετρία
Οικογένεια	Latent structure	Latent structure
Έτος προέλευσης	1999 (omega); 2007 (polytomous extension)	2007
Δημιουργός	Roderick P. McDonald (omega); extension for polytomous items by Zumbo, Gadermann & Zeisser	Bruno D. Zumbo and colleagues
Τύπος	Reliability coefficient	Internal consistency reliability estimation
Θεμελιώδης πηγή	Zumbo, B. D., Gadermann, A. M., & Zeisser, C. (2007). Ordinal versions of coefficients alpha and theta as measures of internal consistency for Likert rating scales. Journal of Modern Applied Statistical Methods, 6(1), 21–29.	Zumbo, B. D., Gadermann, A. M. & Zeisser, C. (2007). Ordinal versions of coefficients alpha and theta as measures of internal consistency for Likert rating scales. Journal of Modern Applied Statistical Methods, 6(1), 21–29.
Εναλλακτικές ονομασίες	ordinal omega, omega for polytomous items, categorical omega, omega polychoric	ordinal alpha, polychoric reliability, reliability for ordinal scales, ORA
Συναφείς	3	5
Σύνοψη	Polytomous McDonald's omega estimates the internal consistency reliability of a scale composed of ordinal (polytomous) items — such as Likert-type responses — by computing omega from a factor model fitted to the polychoric correlation matrix rather than the Pearson correlation matrix, yielding estimates that are unbiased by the discreteness of item responses.	Ordinal reliability analysis estimates the internal consistency of scales whose items are measured on ordered-category (Likert-type) response formats. By basing computations on polychoric correlations rather than Pearson correlations, it corrects for the attenuation that standard Cronbach's alpha produces when responses are discrete and non-normal.