Abstract

Item response theory (IRT) models are some of the most widely used psychometric models. This is certainly the case in large-scale educational assessment. Over the past two decades these models have formed the core of many of the high-stakes assessments in K-12 education (and beyond). While there has always been some interest in applying these models to social science assessment beyond education, the progress on that front has lagged considerably. The project that is at the core of this book, the Patient Reported Outcomes Measurement Information System (PROMIS^®, Cella et al., 2007), was a significant milestone in bringing the rigor of modern psychometric methods to the area of patient-reported outcomes (PROs). Not only did PROMIS^® create a number of calibrated item banks and an adaptive testing system, the publications accompanying them laid out a blueprint for future researchers to incorporate these more advanced psychometric models into their own research (Cella et al., 2010).