השוואת שיטות

	ניתוח פונקציונליות פריט דיפרנציאלית (DIF) של קיצורי-צורה (Short-Form DIF)	תפקוד פריט דיפרנציאלי (DIF)
תחום	פסיכומטריה	פסיכומטריה
משפחה	Latent structure	Latent structure
שנת המקור	1970s–1990s (DIF); short-form context developed in parallel with scale abbreviation literature	1970s–1993
הוגה השיטה	Angoff, W. H. and subsequent DIF methodologists	William H. Angoff and colleagues (ETS); systematized by Holland & Wainer
סוג	Item bias / measurement fairness analysis	Item-level bias detection
מקור מכונן	Millsap, R. E. (2012). Statistical Approaches to Measurement Invariance. Routledge. ISBN: 978-0-8058-4507-0	Holland, P. W. & Wainer, H. (Eds.) (1993). Differential Item Functioning. Lawrence Erlbaum Associates. ISBN: 978-0805809589
כינויים	Short-form DIF, abbreviated scale DIF, DIF in short forms, short-scale DIF detection	DIF, item bias analysis, measurement non-equivalence, item-level measurement bias
קשורות	6	5
תקציר	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.	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.