Σύγκριση μεθόδων

	Διαχρονική Λειτουργία Διαφορικών Στοιχείων (Longitudinal DIF)	Δοκιμή Διαχρονικής Αμεταβλητότητας Μέτρησης
Πεδίο	Ψυχομετρία	Ψυχομετρία
Οικογένεια	Latent structure	Latent structure
Έτος προέλευσης	1980s–2000s	1993
Δημιουργός	Multiple contributors; foundational DIF methods by Lord (1980) extended to longitudinal designs	William Meredith
Τύπος	Item-level bias detection across time	Measurement model testing
Θεμελιώδης πηγή	Millsap, R. E., & Kwok, O. M. (2004). Evaluating the impact of partial factorial measurement invariance on selection in two groups. Psychological Methods, 9(1), 93–115.	Meredith, W. (1993). Measurement invariance, factor analysis and factorial invariance. Psychometrika, 58(4), 525–543.
Εναλλακτικές ονομασίες	longitudinal DIF, DIF across time, temporal DIF, longitudinal item bias	LMI, longitudinal invariance, measurement equivalence across time, temporal measurement invariance
Συναφείς	6	3
Σύνοψη	Longitudinal differential item functioning detects whether individual test or scale items behave differently across measurement occasions for the same respondents. It extends standard DIF methodology to repeated-measures designs, ensuring that observed change scores genuinely reflect construct change rather than shifts in item characteristics over time.	Longitudinal measurement invariance testing determines whether a psychological scale measures the same construct in the same way across two or more time points. It is a prerequisite for interpreting mean-level change scores in panel and repeated-measures studies, ensuring that observed change reflects true change in the construct rather than drift in the measurement instrument.