ABSTRACT
Item response theory (IRT) is the canonical example of what has been called modern test theory, marked by latent-variable models and probability-based reasoning. It is the workhorse of contemporary large-scale educational assessment as well, supporting such innovations as adaptive testing and matrix sampling of tasks. Does IRT provide quantitative measures of psychological attributes of students? This chapter examines this question in light of both (a) developments in the theory of psychological measurement and (b) the sociocognitive view of educational measurement modeling developed in the preceding chapters. Topics include different senses of the term “measurement” that are variously held, conjoint measurement theory, Georg Rasch’s approach to educational and psychological measurement, and the integration of cognitive theory into IRT and assessment.
