Module 21. Applications of Item Response Theory: Computer Adaptive Testing and Differential Item Functioning
Two major applications of item response theory (IRT) noted in Module 20 were the development of computer adaptive testing (CAT) and the examination of differential item functioning (DIF). There are numerous other less wellknown applications of IRT beyond these, such as appropriateness measurement and test equating, which unfortunately we do not have the space to expand on here. However, given the technical-and, to many, mysterious-nature of IRT, we believe that it is important to discuss at least a few of the more prominent applications of this technique. In doing so, we hope to demonstrate IRT’s practical relevance and entice you to learn more about IRT and its application to a variety of measurement issues. As with IRT itself, however, both of these topics are rather involved. Therefore, we provide only a brief overview of these topics and refer you to Camilli and Shepard (1994), de Ayala (2009), Embretson and Reise (2000), Raju and Ellis (2002), and Wainer, Dorans, Flaugher, Green, and Mislevy (2000) for more detailed discussions on the nuts and bolts of implementing such procedures in practice.