Psychometric Evaluation of the Eysenck Personality Questionnaire

Abstract

The Eysenck Personality Questionnaire (EPQ) was administered to 675 undergraduate psychology students, and data were examined with regard to central tendency and variability, scale intercorrelations, the internal consistencies of the scales, and the factor structure of the instrument by using two analytical approaches. Scale means and standard deviations were comparable to those found with other samples, and the scales were generally orthogonal to one another. Although the Extraversion, Neuroticism, and Lie scales appeared internally consistent, the Psychoticism scales demonstrated relatively low reliability. A serious problem appears to exist in the factor structure of the EPQ and thus with a meaningful interpretation of its factorial validity. The Psychoticism scale, in particular, needs to be reassessed as to both its item composition and the underlying construct it purports to measure. clinical implications of the findings are presented.