手法を比較

	順序型探索的因子分析	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	1978–1984	1952–1968
提唱者	Bengt Muthén	Frederic M. Lord (and Allan Birnbaum for the 2PL/3PL models)
種類	Latent variable / dimension reduction	Probabilistic measurement model
原典	Flora, D. B. & Curran, P. J. (2004). An empirical evaluation of alternative methods of estimation for confirmatory factor analysis with ordinal data. Psychological Methods, 9(4), 466–491.	Lord, F. M. & Novick, M. R. (1968). Statistical Theories of Mental Test Scores. Addison-Wesley.
別名	ordinal factor analysis, polychoric EFA, categorical EFA, EFA for ordinal data	IRT, latent trait theory, item characteristic curve theory, modern test theory
関連	5	5
概要	Ordinal exploratory factor analysis discovers latent factors underlying a set of ordinal items — typically Likert scales — by computing polychoric correlations among the items and then applying a weighted least squares estimator. It avoids the distortions that arise when continuous EFA methods are naively applied to ordered categorical responses.	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.