手法を比較

	ロバストクロンバックのα	項目応答理論 (IRT)
分野	心理測定学	心理測定学
系統	Latent structure	Latent structure
提唱年	2002–2016	1952–1968
提唱者	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)
種類	Robust reliability coefficient	Probabilistic measurement model
原典	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.
別名	robust alpha, outlier-resistant Cronbach's alpha, robust internal consistency, robust coefficient alpha	IRT, latent trait theory, item characteristic curve theory, modern test theory
関連	3	5
概要	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.