手法を比較

	マクドナルドのオメガ（ω）信頼性係数	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	1999	1951
提唱者	Roderick P. McDonald	Lee J. Cronbach
種類	Reliability coefficient / latent variable model	Reliability / internal consistency coefficient
原典	McDonald, R. P. (1999). Test Theory: A Unified Treatment. Lawrence Erlbaum Associates. ISBN: 978-0805830750	Cronbach, L. J. (1951). Coefficient alpha and the internal structure of tests. Psychometrika, 16(3), 297–334.
別名	omega reliability, ω coefficient, omega total, omega hierarchical	coefficient alpha, alpha reliability, internal consistency reliability, Güvenilirlik Analizi (Cronbach Alpha)
関連	6	4
概要	McDonald's omega is a factor-analysis-based reliability coefficient introduced by Roderick P. McDonald (1999) that quantifies the internal consistency of a composite score without requiring the restrictive assumption that all items contribute equally to the latent factor. It yields two complementary indices: ω_total, which captures overall reliability of the sum score, and ω_hierarchical (ωh), which reports how much of the composite's variance is explained specifically by a single general factor.	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.