BAKR HUSSEIN
DOI: https://doi.org/This article provides a comprehensive critical analysis of Cronbach's alpha from a theoretical and conceptual perspective. It traces the historical development of the coefficient from its roots in Kuder and Richardson's KR-20 equations to Cronbach's (1951) generalization, which made it applicable to multilevel data. It discusses prerequisites for its proper use, such as unidimensionality and error independence, and highlights common interpretation errors, such as considering it as evidence of validity rather than reliability. It also presents criticisms of it from an Item Response Theory (IRT) perspective, which reveal its limitations due to its sample dependence and assumption of consistent accuracy across all subjects. Conversely, the article reviews more accurate contemporary alternatives, such as McDonald's Omega and IRT-based reliability indices, offering practical recommendations that call for factor analysis before calculating alpha, the use of concomitant coefficients, and the adoption of modern models to ensure a more responsible assessment of the reliability of measurement instruments.
