The Relation Between Item Format and the Structure of the Eysenck Personality Inventory
Date of Original Version
A Likert seven-choice response format for per sonality inventories allows finer distinctions by sub jects than the traditional two-choice format. The Eysenck Personality Inventory was employed in the present study to test the hypothesis that use of the expanded format would result in a clearer and more accurate indication of test structure. The sub jects, volunteers in a psychology course, took the standard two-choice version of the EPI and a seven-choice version one week apart, with the order counter-balanced. A principal components analysis with a varimax rotation yielded two components for the two-choice format, clearly identifiable as Eysenck's “Neuroticism” and “Extraversion” which together accounted for 18% of the variance. The seven-choice version resulted in six components ac counting for 46% of the variance. The expanded format suggested inadequacies in the structure of the EPI, defined the factor structure more clearly, and explained a greater proportion of the variance. It thus demonstrated the apparent advantages of the multiple-response format for scale construction. © 1978, Sage Publications. All rights reserved.
Applied Psychological Measurement
Velicer, Wayne F., and John F. Stevenson. "The Relation Between Item Format and the Structure of the Eysenck Personality Inventory." Applied Psychological Measurement 2, 2 (1978): 293-304. doi:10.1177/014662167800200210.