Methoden vergleichen

	Ordinal Differential Item Functioning (Ordinal DIF)	Item Response Theory (IRT)
Fachgebiet	Psychometrie	Psychometrie
Familie	Latent structure	Latent structure
Entstehungsjahr	1999-2001	1952–1968
Urheber	Zumbo (logistic extension) and Penfield (Mantel generalization)	Frederic M. Lord (and Allan Birnbaum for the 2PL/3PL models)
Typ	Item bias detection for ordered-category items	Probabilistic measurement model
Wegweisende Quelle	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.
Aliasnamen	ordinal DIF, polytomous DIF, DIF for ordered categories, ordinal logistic DIF	IRT, latent trait theory, item characteristic curve theory, modern test theory
Verwandt	6	5
Zusammenfassung	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.