手法を比較

	Differential Distractor Functioning	項目応答理論における項目特性曲線（ICC）の差
分野	Education	心理測定学
系統	Latent structure	Latent structure
提唱年	2008	1970s–1993
提唱者	Item-bias methodology (Green, Crone & Folk; Penfield)	William H. Angoff and colleagues (ETS); systematized by Holland & Wainer
種類	Group-difference analysis of the incorrect options (distractors) of multiple-choice items	Item-level bias detection
原典	Penfield, R. D. (2008). An odds ratio approach for assessing differential distractor functioning effects under the nominal response model. Journal of Educational Measurement, 45(3), 247–269.	Holland, P. W. & Wainer, H. (Eds.) (1993). Differential Item Functioning. Lawrence Erlbaum Associates. ISBN: 978-0805809589
別名	DDF, Distractor-Level DIF, Differential Option Functioning, Distractor Functioning Analysis	DIF, item bias analysis, measurement non-equivalence, item-level measurement bias
関連	4	5
概要	Differential distractor functioning (DDF) extends test-fairness analysis from the correct answer to the wrong ones. It asks whether examinees of equal ability but different group membership are differentially attracted to particular distractors (incorrect options) of a multiple-choice item. By analyzing option-level rather than just right/wrong responses, DDF can detect bias that ordinary differential item functioning misses and, crucially, help explain why an item functions differently — pointing to the specific wrong option luring one group. Penfield's odds-ratio approach under the nominal response model is a standard tool.	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.