ABSTRACT
The term item response theory (IRT) refers to a set of psychometric procedures that serve as an alternative to traditional classical test theory (CTT) methods of analyzing psychological tests and test items. In educational and aptitude testing, IRT procedures are well known and well established. This fact can be validated by pointing to the existence of several introductory texts on IRT (e.g., Hambleton, Swaminathan, & Rogers, 1991; Lord, 1980) and through examining the preponderance of IRT-based research in journals such as Applied Psychological Measurement or the Journal of Educational Measurement. Despite its proliferation in educational assessment, only recently has IRT been applied in the domain of typical performance or personality assessment (cf. Steinberg & Thissen, 1995). The goal of this chapter, therefore, is to describe and discuss some applications of IRT measurement models in personality assessment and to highlight advantages and disadvantages that might be accrued through such application. In the subsequent section, a brief introduction to IRT models as they may be applied to understanding the psychometric properties of personality tests and test items is provided.
