השוואת שיטות

	ניתוח פריטים רובסטי	תפקוד פריט דיפרנציאלי (DIF)
תחום	פסיכומטריה	פסיכומטריה
משפחה	Latent structure	Latent structure
שנת המקור	1980s–2000s	1970s–1993
הוגה השיטה	Robust methods tradition (Huber, Hampel, Tukey); applied to item analysis by Wilcox and colleagues	William H. Angoff and colleagues (ETS); systematized by Holland & Wainer
סוג	Diagnostic / item-level evaluation	Item-level bias detection
מקור מכונן	Wilcox, R. R. (2012). Introduction to Robust Estimation and Hypothesis Testing (3rd ed.). Academic Press. ISBN: 978-0123869838	Holland, P. W. & Wainer, H. (Eds.) (1993). Differential Item Functioning. Lawrence Erlbaum Associates. ISBN: 978-0805809589
כינויים	robust item statistics, outlier-resistant item analysis, robust classical item analysis	DIF, item bias analysis, measurement non-equivalence, item-level measurement bias
קשורות	5	5
תקציר	Robust item analysis applies outlier-resistant statistical methods to the evaluation of individual test or scale items. Instead of classical means and Pearson correlations — both sensitive to extreme scores — it uses trimmed means, Winsorized correlations, or M-estimators to obtain item difficulty and item-total discrimination indices that remain stable when respondent distributions are skewed or contaminated by outliers.	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.