Sammenlign metoder

	Kortforms differentiel itemfunktion (Short-Form DIF)	Kortform-målingsinvarians
Fagområde	Psykometri	Psykometri
Familie	Latent structure	Latent structure
Oprindelsesår	1970s–1990s (DIF); short-form context developed in parallel with scale abbreviation literature	2000s
Ophavsperson	Angoff, W. H. and subsequent DIF methodologists	Adapted from Vandenberg & Lance (2000) and Millsap & Kwok (2004) invariance framework applied to short-form scales
Type	Item bias / measurement fairness analysis	Measurement equivalence testing
Oprindelig kilde	Millsap, R. E. (2012). Statistical Approaches to Measurement Invariance. Routledge. ISBN: 978-0-8058-4507-0	Millsap, R. E., & Kwok, O. M. (2004). Evaluating the impact of partial factor loading and intercept invariance on selection in two populations. Psychological Methods, 9(1), 93–115.
Aliasser	Short-form DIF, abbreviated scale DIF, DIF in short forms, short-scale DIF detection	SF-MI, abbreviated scale invariance, short-form factorial invariance, brief measure invariance
Relaterede	6	6
Resumé	Short-form differential item functioning (DIF) analysis examines whether individual items in an abbreviated scale function equivalently across demographic or subgroup comparisons. When a scale is shortened, retained items must still behave fairly for all relevant groups — DIF analysis verifies this, ensuring that score differences reflect true ability or trait differences rather than item bias.	Short form measurement invariance testing evaluates whether an abbreviated version of a psychological scale measures the same latent construct equivalently across groups or conditions. It applies the hierarchical multigroup confirmatory factor analysis invariance sequence — configural, metric, scalar, and strict — specifically to short-form instruments, ensuring that brevity does not introduce measurement bias when comparing subgroups.