Using Item Response Theory to Develop a 60-Item Representation of the NEO PI–R Using the International Personality Item Pool: Development of the IPIP–NEO–60

Given advantages of freely available and modifiable measures, an increase in the use of measures developed from the International Personality Item Pool (IPIP), including the 300-item representation of the Revised NEO Personality Inventory (NEO PI–R; Costa &; McCrae, 1992a Costa, P., &; McCrae, R. (1992a). The five-factor model of personality and its relevance to personality disorders. Journal of Personality Disorders, 6, 343–359.[Crossref], [Web of Science ®] , [Google Scholar]) has occurred. The focus of this study was to use item response theory to develop a 60-item, IPIP-based measure of the Five-Factor Model (FFM) that provides equal representation of the FFM facets and to test the reliability and convergent and criterion validity of this measure compared to the NEO Five Factor Inventory (NEO-FFI). In an undergraduate sample (n = 359), scores from the NEO-FFI and IPIP–NEO–60 demonstrated good reliability and convergent validity with the NEO PI–R and IPIP–NEO–300. Additionally, across criterion variables in the undergraduate sample as well as a community-based sample (n = 757), the NEO-FFI and IPIP–NEO–60 demonstrated similar nomological networks across a wide range of external variables (r_ICC = .96). Finally, as expected, in an MTurk sample the IPIP–NEO–60 demonstrated advantages over the Big Five Inventory–2 (Soto &; John, 2017 Soto, C. J., &; John, O. P. (2017). The next Big Five Inventory (BFI–2): Developing and assessing a hierarchical model with 15 facets to enhance bandwidth, fidelity, and predictive power. Journal of Personality and Social Psychology, 113, 117–143.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; n = 342) with regard to the Agreeableness domain content. The results suggest strong reliability and validity of the IPIP–NEO–60 scores.