手法を比較

	3パラメータロジスティックIRTモデル（3PL）	クロンバックのα（信頼性分析）
分野	心理測定学	統計学
系統	Latent structure	Latent structure
提唱年	1968	1951
提唱者	Allan Birnbaum	Lee J. Cronbach
種類	Item response model / latent trait model	Reliability / internal consistency coefficient
原典	Birnbaum, A. (1968). Some latent trait models and their use in inferring an examinee's ability. In F. M. Lord & M. R. Novick (Eds.), Statistical theories of mental test scores (pp. 397–479). Addison-Wesley.	Cronbach, L. J. (1951). Coefficient alpha and the internal structure of tests. Psychometrika, 16(3), 297–334.
別名	3PL IRT — Üç Parametreli Madde Tepki Modeli, three-parameter logistic model, 3PLM, Birnbaum model	coefficient alpha, alpha reliability, internal consistency reliability, Güvenilirlik Analizi (Cronbach Alpha)
関連	5	4
概要	The three-parameter logistic (3PL) model, introduced by Allan Birnbaum in 1968, is an item response theory model that describes the probability of a correct response to a binary test item as a function of three item-level parameters — difficulty, discrimination, and a lower asymptote representing guessing — and one person-level parameter representing latent ability.	Cronbach's alpha is a coefficient of internal consistency that quantifies the degree to which a set of items on a scale measures the same underlying construct. Introduced by Lee J. Cronbach in 1951, it remains the most widely reported reliability index in social-science, health, and educational research.