Developing and Measuring IS Scales Using Item Response Theory

Information Systems (IS) research frequently uses survey data to measure the interplay between technological systems and human beings. Researchers have developed sophisticated procedures to build and validate multi-item scales that measure latent constructs. Most studies use classical test theory (CTT), which suffers from several theoretical shortcomings. We discuss these problems and present item response theory (IRT) as a viable alternative. Subsequently, we use the CTT approach as well as Rasch models (a class of restrictive IRT models) to develop a scale for measuring the hedonic aspects of websites. The results illustrate how IRT can not only be successfully applied in IS research but also provide improved results over CTT approaches.