Confronta i metodi

	Analisi degli item per sottogruppi	Teoria della risposta all'item (IRT)
Campo	Psicometria	Psicometria
Famiglia	Latent structure	Latent structure
Anno di origine	1986	1952–1968
Ideatore	Classical test theory tradition; systematised by Crocker & Algina (1986)	Frederic M. Lord (and Allan Birnbaum for the 2PL/3PL models)
Tipo	Comparative item-level analysis	Probabilistic measurement model
Fonte seminale	Crocker, L. & Algina, J. (1986). Introduction to Classical and Modern Test Theory. Holt, Rinehart and Winston. ISBN: 978-0030616341	Lord, F. M. & Novick, M. R. (1968). Statistical Theories of Mental Test Scores. Addison-Wesley.
Alias	MGIA, group-comparative item analysis, subgroup item analysis, cross-group item analysis	IRT, latent trait theory, item characteristic curve theory, modern test theory
Correlati	6	5
Sintesi	Multi-group item analysis computes classical item statistics — difficulty, discrimination, and corrected item-total correlations — separately for each subgroup in a sample and then compares those statistics across groups. It is a standard diagnostic step in scale development and test fairness evaluation, revealing items that behave differently for men versus women, across age cohorts, or across cultural groups before more formal DIF testing.	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.