This book provides a concise, unified presentation of adaptive design theories, uses SAS and R for the design and simulation of adaptive trials, and illustrates how to master different adaptive designs through real-world examples. It emphasizes the relationships among different methods; presents current regulatory views; discusses the challenges in planning, executing, analyzing, and reporting adaptive designs; and features Bayesian decision theory to optimize adaptive designs and programs. The author also explores controversial issues surrounding statistical theories as well as fruitful avenues for future research and applications of adaptive designs.