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 ) 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...