Sammenlign metoder

	Testing for ordinal measurement invariance	Differensiert varefunksjonering (DIF)
Fagfelt	Psykometri	Psykometri
Familie	Latent structure	Latent structure
Opprinnelsesår	1984–2011	1970s–1993
Opphavsperson	Roger Millsap; Bengt Muthén	William H. Angoff and colleagues (ETS); systematized by Holland & Wainer
Type	Multi-group model comparison	Item-level bias detection
Opprinnelig kilde	Millsap, R. E. (2011). Statistical Approaches to Measurement Invariance. Routledge. ISBN: 978-1848728936	Holland, P. W. & Wainer, H. (Eds.) (1993). Differential Item Functioning. Lawrence Erlbaum Associates. ISBN: 978-0805809589
Alias	ordinal MI, measurement invariance for ordinal data, ordinal CFA invariance, categorical measurement invariance	DIF, item bias analysis, measurement non-equivalence, item-level measurement bias
Relaterte	6	5
Sammendrag	Ordinal measurement invariance testing evaluates whether a multi-group confirmatory factor model holds equivalent measurement properties across groups when scale items are ordinal — such as Likert-type response scales. It uses polychoric correlations and categorical estimators (WLSMV/DWLS) rather than Pearson-based methods, correcting the systematic bias that arises when ordinal data are treated as continuous.	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.