Σύγκριση μεθόδων

	Πολυομαδική Θεωρία Απόκρισης Αντικειμένων (MG-IRT)	Διαφορική Λειτουργία Αντικειμένου (DIF)
Πεδίο	Ψυχομετρία	Ψυχομετρία
Οικογένεια	Latent structure	Latent structure
Έτος προέλευσης	1990s	1970s–1993
Δημιουργός	Multiple contributors; formalized by Birnbaum (1968) for IRT; multi-group extensions developed through 1980s–1990s	William H. Angoff and colleagues (ETS); systematized by Holland & Wainer
Τύπος	Latent trait / measurement invariance	Item-level bias detection
Θεμελιώδης πηγή	Embretson, S. E. & Reise, S. P. (2000). Item Response Theory for Psychologists. Lawrence Erlbaum Associates. ISBN: 978-0805828191	Holland, P. W. & Wainer, H. (Eds.) (1993). Differential Item Functioning. Lawrence Erlbaum Associates. ISBN: 978-0805809589
Εναλλακτικές ονομασίες	MG-IRT, multiple-group IRT, multi-group latent trait model, IRT across groups	DIF, item bias analysis, measurement non-equivalence, item-level measurement bias
Συναφείς	6	5
Σύνοψη	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.	Differential item functioning identifies test or survey items that behave differently for examinees from different groups — such as gender, ethnicity, or language background — after controlling for the underlying ability or trait being measured. DIF analysis is essential for fairness evaluation in educational testing and psychological scale development.