So sánh phương pháp

	Phát triển thang đo đa cấp	Chức năng biệt lập của mục (Differential Item Functioning - DIF)
Lĩnh vực	Trắc lượng tâm lý	Trắc lượng tâm lý
Họ	Latent structure	Latent structure
Năm ra đời	1969–1982	1970s–1993
Người khởi xướng	Samejima, F.; Masters, G. N. (independently)	William H. Angoff and colleagues (ETS); systematized by Holland & Wainer
Loại	Psychometric scale construction	Item-level bias detection
Công trình gốc	Embretson, S. E. & Reise, S. P. (2000). Item Response Theory for Psychologists. Lawrence Erlbaum Associates. ISBN: 978-0805828191	Holland, P. W. & Wainer, H. (Eds.) (1993). Differential Item Functioning. Lawrence Erlbaum Associates. ISBN: 978-0805809589
Tên gọi khác	polytomous item development, ordered-category scale construction, rating scale development, multi-category item development	DIF, item bias analysis, measurement non-equivalence, item-level measurement bias
Liên quan	6	5
Tóm tắt	Polytomous scale development is the systematic construction and validation of measurement instruments whose items have three or more ordered response categories — such as Likert-type, rating, or partial-credit items. It applies polytomous item response theory models or ordinal factor analysis methods to evaluate item quality, estimate latent trait levels, and build a psychometrically sound scale.	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.