Written especially for psychometricians, scale developers, and practitioners interested in applications of Bayesian estimation and model checking of item response theory (IRT) models, this book teaches you how to accomplish all of this with the SAS MCMC Procedure. Working through this book's examples, you will learn how to write the PROC MCMC programming code to estimate various simple and more complex item response theory models, including the choice and specification of prior distributions, specification of the likelihood model, and interpretation of results. Numerous programs for conducting these analyses are provided and annotated so that you can easily modify them for your applications.