Item grouping and item randomization in personality measurement

• We examined the effect of item order on a personality scale.
• We assessed internal consistency and scale-level correlations.
• Item order slightly affected scale-level correlations.
• Item order did not affect internal psychometrics.

This paper describes a study examining the impact of item order in personality measurement on reliability, measurement equivalence and scale-level correlations. A large sample of university students completed one of three forms of the International Personality Item Pool version of the Big Five personality inventory: items sorted at random, items sorted by factor, and items cycled through factors. Results showed that the underlying measurement model and the internal consistency of the IPIP-Big Five scale was unaffected by differences in item order. Also, most of the scale-level correlations among factors were not significantly different across forms. Implications for the administration of tests and interpretation of test scores are discussed, and future research directions are offered.