手法を比較

	2母数ロジスティックIRTモデル（2PL）	確認的因子分析（CFA）
分野	心理測定学	心理測定学
系統	Latent structure	Latent structure
提唱年	1980	1969
提唱者	Frederic M. Lord	Karl Gustav Jöreskog
種類	Item response model / latent trait model	Hypothesis-testing latent variable model
原典	Lord, F. M. (1980). Applications of Item Response Theory to Practical Testing Problems. Erlbaum.	Jöreskog, K. G. (1969). A general approach to confirmatory maximum likelihood factor analysis. Psychometrika, 34(2), 183–202.
別名	two-parameter logistic model, 2PL model, 2PL IRT — İki Parametreli Madde Tepki Modeli	CFA, confirmatory FA, measurement model, restricted factor analysis
関連	6	4
概要	The two-parameter logistic item response model, formalised by Frederic Lord (1980), describes the probability that a respondent answers a binary test item correctly as a smooth S-shaped function of the respondent's latent ability. By estimating a separate discrimination parameter for each item alongside a difficulty parameter, 2PL allows items to differ in how sharply they distinguish high- from low-ability respondents — making it the standard model for large-scale educational and psychological assessments.	Confirmatory factor analysis tests a researcher-specified factor structure against observed data. Unlike exploratory approaches, the researcher decides in advance which indicators load on which latent factor, and the model is evaluated by how closely the implied covariance matrix reproduces the sample covariance matrix. CFA is central to scale validation, construct validity assessment, and measurement invariance testing.