手法を比較

	多群差項目機能 (MG-DIF)	多群項目反応理論（MG-IRT）
分野	心理測定学	心理測定学
系統	Latent structure	Latent structure
提唱年	1980s-1990s	1990s
提唱者	Shealy & Stout (SIBTEST framework); Lord (IRT-based DIF)	Multiple contributors; formalized by Birnbaum (1968) for IRT; multi-group extensions developed through 1980s–1990s
種類	Measurement bias detection	Latent trait / measurement invariance
原典	Millsap, R. E. (2012). Statistical Approaches to Measurement Invariance. Routledge. ISBN: 978-1848728936	Embretson, S. E. & Reise, S. P. (2000). Item Response Theory for Psychologists. Lawrence Erlbaum Associates. ISBN: 978-0805828191
別名	MG-DIF, multi-group DIF, differential item functioning across groups, multiple-group DIF analysis	MG-IRT, multiple-group IRT, multi-group latent trait model, IRT across groups
関連	6	6
概要	Multi-group differential item functioning examines whether test or scale items function equivalently across three or more distinct groups — such as gender, ethnicity, or country — after matching respondents on the underlying trait being measured. Items that behave differently across groups threaten fair measurement and valid score comparisons.	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.