The unidimensionality of a measurement instrument: A factorial perspective

• Autor: Burga León, Andrés
• Formato: artículo
• Fecha de Publicación: 2006
• Institución: Pontificia Universidad Católica del Perú
• Repositorio: Revistas - Pontificia Universidad Católica del Perú
• Lenguaje: español
• OAI Identifier: oai:revistaspuc:article/642
• Enlace del recurso: http://revistas.pucp.edu.pe/index.php/psicologia/article/view/642
• Nivel de acceso: acceso abierto
• Materia: Unidimensionality; Classical Test Theory; factor analysis; tetrachoric correlations; polychoric correlations; unidimensionalidad; Teoría Clásica de los Tests; análisis factorial; correlaciones tetracóricas; correlaciones policóricas

This article explains what we mean by the unidimensionality of a measurement instrument, therefore we present some definitions and  theoretical contributions about this subject. Factor analysis is proposed as one of the many methods for assessing the unidimensionality of a measurement instrument. The use of Pearson correlations matrices on item-level factor analysis is identified as an important problem. Those correlations are problematic because items didn’t carry out the necessary assumptions in order to apply the Pearson correlation: interval-level measurement and normal distribution of the variable. As an alternative we propose and exemplify the use of tetrachoric and polychoric correlations.