Methoden vergleichen

	Robuste Cronbachs Alpha	Item Response Theory (IRT)
Fachgebiet	Psychometrie	Psychometrie
Familie	Latent structure	Latent structure
Entstehungsjahr	2002–2016	1952–1968
Urheber	Derived from Lee J. Cronbach (1951); robust variants formalized by Yuan & Bentler (2002) and Zhang & Yuan (2016)	Frederic M. Lord (and Allan Birnbaum for the 2PL/3PL models)
Typ	Robust reliability coefficient	Probabilistic measurement model
Wegweisende Quelle	Yuan, K.-H., & Bentler, P. M. (2002). On robustness of the normal-theory based asymptotic distributions of three reliability coefficient estimates. Psychometrika, 67(2), 251–268.	Lord, F. M. & Novick, M. R. (1968). Statistical Theories of Mental Test Scores. Addison-Wesley.
Aliasnamen	robust alpha, outlier-resistant Cronbach's alpha, robust internal consistency, robust coefficient alpha	IRT, latent trait theory, item characteristic curve theory, modern test theory
Verwandt	3	5
Zusammenfassung	Robust Cronbach's alpha adapts the classical internal consistency coefficient to data that violate the assumption of multivariate normality or contain influential outliers. By replacing the conventional sample covariance matrix with a robust counterpart, it yields a reliability estimate that is resistant to distortion by non-normal response distributions, contaminated observations, or small violations of model assumptions common in applied psychometric work.	Item response theory models the probability that a respondent answers an item correctly (or endorses it) as a function of the respondent's latent trait level and the item's own statistical properties — difficulty, discrimination, and guessing. Unlike classical test theory, IRT places persons and items on the same scale, yielding measurement that is sample-independent for items and test-independent for persons.