Investigating the quality of items in CAT using nonparametric IRT

I discuss the applicability of nonparametric item response theory (IRT) models to the quality of item pool development in the context of CAT, and I contrast these models with parametric IRT models. I also show how nonparametric IRT models can easily be applied and how misleading results from parametric IRT models can be avoided. I recommend the use of nonparametric IRT modeling to routinely investigate the quality of item pools.