Introducing Bayesian methods, this book emphasizes that the primary role of statistics is to provide appropriate tools for addressing scientific questions. As such, the authors present a collaborative approach to data analysis involving both scientists and statisticians that can be used to model unknown parameters using scientific information, called prior information or apriori. Keeping the mathematics to a minimum, the text focuses on applications, statistical ideas, models, and interpretations. It features WinBUGS throughout the computational problems and uses Monte Carlo methods for all simulations.