Advances in clinical personality measurement: An item response theory analysis of the MMPI-2 PSY-5 scales

Item response theory (IRT) provides valuable methods for the analysis of th e psychometric properties of a psychological measure. To date, however, the se methods have not been used frequently by personality assessment research ers, in part because many researchers have not been introduced to the metho ds and in part because most of the development of IRT has taken place in ap plied education assessment settings, resulting in terminology that is abili ty focused rather than trait focused. The purpose of this article is twofol d. First, an overview of IRT is presented, highlighting the concepts of the three-parameter IRT model, item and test information, and conditional stan dard error of measurement. Second, the psychometric properties of the (MMPI -2) PSY-5 scales are examined to demonstrate IRT's value.