手法を比較

	順序項目分析	項目応答理論 (IRT)
分野	心理測定学	心理測定学
系統	Latent structure	Latent structure
提唱年	1950s–1980s	1952–1968
提唱者	Classical test theory tradition (Guilford, Nunnally, and others)	Frederic M. Lord (and Allan Birnbaum for the 2PL/3PL models)
種類	Item-level diagnostic	Probabilistic measurement model
原典	Nunnally, J. C. & Bernstein, I. H. (1994). Psychometric Theory (3rd ed.). McGraw-Hill. ISBN: 978-0070474659	Lord, F. M. & Novick, M. R. (1968). Statistical Theories of Mental Test Scores. Addison-Wesley.
別名	item analysis for ordinal data, polytomous item analysis, Likert item analysis, OIA	IRT, latent trait theory, item characteristic curve theory, modern test theory
関連	6	5
概要	Ordinal item analysis evaluates each individual item in a rating-scale or Likert-type instrument using descriptive and correlational statistics suited to ordered categorical response formats. It guides item selection and refinement by flagging items with problematic difficulty, poor discrimination, or low corrected item-total correlations before reliability and validity studies proceed.	Item response theory models the probability that a respondent answers an item correctly (or endorses it) as a function of the respondent's latent trait level and the item's own statistical properties — difficulty, discrimination, and guessing. Unlike classical test theory, IRT places persons and items on the same scale, yielding measurement that is sample-independent for items and test-independent for persons.