手法を比較

	一般化可能性理論（G理論）	級内相関係数（ICC）
分野	心理測定学	統計学
系統	Latent structure	Hypothesis test
提唱年	1963	1979
提唱者	Lee J. Cronbach and colleagues	Shrout & Fleiss
種類	ANOVA-based variance-component framework	Reliability / agreement coefficient
原典	Brennan, R. L. (2001). Generalizability Theory. Springer.	Shrout, P.E. & Fleiss, J.L. (1979). Intraclass Correlations: Uses in Assessing Rater Reliability. Psychological Bulletin, 86(2), 420–428.
別名	Generalizability Theory, G-Study / D-Study framework, Genellenebilirlik Kuramı (G-Kuramı)	ICC, intraclass correlation, rater reliability coefficient, Sınıf İçi Korelasyon Katsayısı (ICC)
関連	6	5
概要	Generalizability Theory, developed by Lee J. Cronbach and colleagues in the 1960s and formalised by Brennan (2001), is an ANOVA-based framework that extends Classical Test Theory by decomposing observed score variance into multiple, separately identified sources of measurement error — such as raters, tasks, occasions, or items — rather than bundling all error into a single undifferentiated term.	The Intraclass Correlation Coefficient (ICC) is a parametric reliability statistic that quantifies the degree of agreement or consistency among repeated measurements or multiple raters on a continuous outcome. The modern six-form taxonomy was established by Shrout and Fleiss in 1979 and remains the standard framework for selecting and reporting ICC in inter-rater reliability, test-retest repeatability, and multilevel-data analyses.