Item format and the structure of the Eysenck Personality Inventory: a replication

A seven-choice response format for personality inventories allows finer distinctions by subjects 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 indication of test structure. A principal components analysis with a varimax rotation retained two components for the two-choice format, clearly identifiable as Eysenck's "Neuroticism" and "Extraversion" which accounted for 16% of the variance. The expanded format retained four components accounting for 28% of the variance.