Compară metode

	Coeficientul de fiabilitate Omega (ω) McDonald	Modelul Rasch
Domeniu	Psihometrie	Psihometrie
Familie	Latent structure	Latent structure
Anul apariției	1999	1960
Autorul original	Roderick P. McDonald	Georg Rasch
Tip	Reliability coefficient / latent variable model	Item Response Theory / Latent trait model
Sursa seminală	McDonald, R. P. (1999). Test Theory: A Unified Treatment. Lawrence Erlbaum Associates. ISBN: 978-0805830750	Rasch, G. (1960). Probabilistic Models for Some Intelligence and Attainment Tests. Danish Institute for Educational Research, Copenhagen.
Denumiri alternative	omega reliability, ω coefficient, omega total, omega hierarchical	1PL IRT, one-parameter logistic model, Rasch Modeli — 1PL IRT, 1PL model
Înrudite	6	6
Rezumat	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.	The Rasch model, introduced by Georg Rasch in 1960, is the simplest member of the Item Response Theory (IRT) family. It assigns a single difficulty parameter to each test item and places both item difficulties and person abilities on the same logit scale, enabling direct, sample-independent comparison of items and persons.