השוואת שיטות

	ניתוח פריטים רב-קבוצתי	תפקוד פריט דיפרנציאלי (DIF)
תחום	פסיכומטריה	פסיכומטריה
משפחה	Latent structure	Latent structure
שנת המקור	1986	1970s–1993
הוגה השיטה	Classical test theory tradition; systematised by Crocker & Algina (1986)	William H. Angoff and colleagues (ETS); systematized by Holland & Wainer
סוג	Comparative item-level analysis	Item-level bias detection
מקור מכונן	Crocker, L. & Algina, J. (1986). Introduction to Classical and Modern Test Theory. Holt, Rinehart and Winston. ISBN: 978-0030616341	Holland, P. W. & Wainer, H. (Eds.) (1993). Differential Item Functioning. Lawrence Erlbaum Associates. ISBN: 978-0805809589
כינויים	MGIA, group-comparative item analysis, subgroup item analysis, cross-group item analysis	DIF, item bias analysis, measurement non-equivalence, item-level measurement bias
קשורות	6	5
תקציר	Multi-group item analysis computes classical item statistics — difficulty, discrimination, and corrected item-total correlations — separately for each subgroup in a sample and then compares those statistics across groups. It is a standard diagnostic step in scale development and test fairness evaluation, revealing items that behave differently for men versus women, across age cohorts, or across cultural groups before more formal DIF testing.	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.