The Emergence of Item Response Theory Models and the Patient Reported Outcomes Measurement Information Systems

Item response theory (IRT) models emerged to solve practical testing problems in large-scale cognitive achievement and aptitude assessment. Within the last decade, an explosion of IRT applications have occurred in the non-cognitive domain. In this report, I highlight the development, implementation, and results of a single project: Patient Reported Outcomes Measurement Information Systems (PROMIS). The PROMIS project reflects the state-of-the-art application of IRT in the non-cognitive domain, and has produced important advancements in patient reported outcomes measurement. However, the project also illustrates challenges that confront researchers wishing to apply IRT to non-cognitive constructs. These challenges are: a) selecting a population to set the metric for interpretation of item parameters, b) working with non-normal quasi-continuous latent traits, and c) working with narrow-bandwidth constructs that potentially have a limited pool of potential indicators. Differences between cognitive and non-cognitive measurement contexts are discussed and directions for future research suggested.