Vertaile menetelmiä

	Moniryhmäinen item response theory (MG-IRT)	Vastausfunktioiden teoria (IRT)
Tieteenala	Psykometriikka	Psykometriikka
Menetelmäperhe	Latent structure	Latent structure
Syntyvuosi	1990s	1952–1968
Kehittäjä	Multiple contributors; formalized by Birnbaum (1968) for IRT; multi-group extensions developed through 1980s–1990s	Frederic M. Lord (and Allan Birnbaum for the 2PL/3PL models)
Tyyppi	Latent trait / measurement invariance	Probabilistic measurement model
Alkuperäislähde	Embretson, S. E. & Reise, S. P. (2000). Item Response Theory for Psychologists. Lawrence Erlbaum Associates. ISBN: 978-0805828191	Lord, F. M. & Novick, M. R. (1968). Statistical Theories of Mental Test Scores. Addison-Wesley.
Rinnakkaisnimet	MG-IRT, multiple-group IRT, multi-group latent trait model, IRT across groups	IRT, latent trait theory, item characteristic curve theory, modern test theory
Liittyvät	6	5
Tiivistelmä	Multi-group item response theory fits IRT models simultaneously across two or more defined groups — such as males and females, or different cultural samples — to determine whether item parameters are invariant across those groups. It is the primary IRT-based framework for testing measurement equivalence and detecting differential item functioning (DIF) at the model level.	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.