Compara mètodes

	Funcionament Diferencial d'Ítems en Formes Curtes (Short-Form DIF)	Teoria de Resposta a l'Ítem de Forma Curta (SF-IRT)
Camp	Psicometria	Psicometria
Família	Latent structure	Latent structure
Any d'origen	1970s–1990s (DIF); short-form context developed in parallel with scale abbreviation literature	1980s–2000s
Autor original	Angoff, W. H. and subsequent DIF methodologists	Multiple contributors; IRT adapted to short-form contexts from Lord & Novick (1968) and subsequent applied psychometricians
Tipus	Item bias / measurement fairness analysis	Latent trait / item calibration model
Font seminal	Millsap, R. E. (2012). Statistical Approaches to Measurement Invariance. Routledge. ISBN: 978-0-8058-4507-0	Embretson, S. E. & Reise, S. P. (2000). Item Response Theory for Psychologists. Lawrence Erlbaum Associates. ISBN: 978-0805828191
Àlies	Short-form DIF, abbreviated scale DIF, DIF in short forms, short-scale DIF detection	SF-IRT, abbreviated scale IRT, short-form calibration, shortened instrument IRT
Relacionats	6	6
Resum	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 item response theory applies IRT calibration and scoring to abbreviated or shortened psychological scales. It uses item information functions to guide which items to retain from a full-length instrument, then estimates latent trait scores from the reduced item set while preserving psychometric rigor and linkage to the full-scale metric.