手法を比較

	順序型項目機能差 (Ordinal DIF)	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	1999-2001	1952–1968
提唱者	Zumbo (logistic extension) and Penfield (Mantel generalization)	Frederic M. Lord (and Allan Birnbaum for the 2PL/3PL models)
種類	Item bias detection for ordered-category items	Probabilistic measurement model
原典	Zumbo, B. D. (1999). A handbook on the theory and methods of differential item functioning (DIF): Logistic regression modeling as a unitary framework for binary and Likert-type (ordinal) item scores. Ottawa: Directorate of Human Resources Research and Evaluation, Department of National Defense.	Lord, F. M. & Novick, M. R. (1968). Statistical Theories of Mental Test Scores. Addison-Wesley.
別名	ordinal DIF, polytomous DIF, DIF for ordered categories, ordinal logistic DIF	IRT, latent trait theory, item characteristic curve theory, modern test theory
関連	6	5
概要	Ordinal differential item functioning analysis detects whether an ordered-category item (such as a Likert-scale question) functions differently across demographic or cultural groups after controlling for the latent trait being measured. It extends classical binary DIF methods to polytomous response formats common in psychological and educational scales.	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.