Psicothema was founded in Asturias (northern Spain) in 1989, and is published jointly by the Psychology Faculty of the University of Oviedo and the Psychological Association of the Principality of Asturias (Colegio Oficial de Psicología del Principado de Asturias).
We currently publish four issues per year, which accounts for some 100 articles annually. We admit work from both the basic and applied research fields, and from all areas of Psychology, all manuscripts being anonymously reviewed prior to publication.
Eduardo Doval1, Carme Viladrich1 and Ariadna Angulo-Brunet2
1 Universitat Autònoma de Barcelona,
2 Universitat Oberta de Catalunya
Background: During the 20th century the alpha coefficient (α) was widely used in the estimation of the internal consistency reliability of test scores. After misuses were identified in the early 21st century alternatives became widespread, especially the omega coefficient (ω). Nowadays, α is re-emerging as an acceptable option for reliability estimation. Method: A review of the recent academic contributions, journal publication habits and recommendations from normative texts was carried out to identify good practices in estimation of internal consistency reliability. Results: To guide the analysis, we propose a three-phase decision diagram, which includes item description, fit of the measurement model for the test, and choice of the reliability coefficient for test score(s). We also provide recommendations on the use of R, Jamovi, JASP, Mplus, SPSS and Stata software to perform the analysis. Conclusions: Both α and ω are suitable for items with approximately normal distributions and approximately unidimensional and congeneric measures without extreme factor loadings. When items show non-normal distributions, strong specific components, or correlated errors, variants of ω are more appropriate. Some require specific data gathering designs. On a practical level we recommend a critical approach when using the software.
Antecedentes: Durante el siglo XX el coeficiente alfa (α) fue ampliamente utilizado en el cálculo de la consistencia interna de las puntuaciones de los test. Después de identificar algunos malos usos, a principios del siglo XXI se difundieron alternativas, especialmente el coeficiente omega (ω). Actualmente α resurge como una opción aceptable. Método: Revisamos aportaciones académicas, hábitos de publicación en revistas y recomendaciones de textos normativos con el fin de identificar buenas prácticas en la estimación de la fiabilidad de consistencia interna. Resultados: Para guiar el análisis, proponemos un diagrama de decisión en tres fases, a saber, descripción de los ítems, ajuste del modelo de medida del test y elección del coeficiente de fiabilidad de las puntuaciones. Para su ejecución proporcionamos recomendaciones sobre el uso de los programas R, Jamovi, JASP, Mplus, SPSS y Stata. Conclusiones: Tanto α como ω son adecuados para ítems que se distribuyen de forma aproximadamente normal y medidas aproximadamente unidimensionales y congenéricas sin cargas factoriales extremas. Cuando los ítems tienen otra distribución, un fuerte componente específico o sus errores están correlacionados, resultan más adecuadas variantes de ω. Algunas de ellas requieren diseños específicos de obtención de datos. A nivel práctico recomendamos un uso crítico del software.
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ENGLISH
https://doi.org/10.7334/psicothema2022.321