Robert N. Rodriguez retired from SAS in 2018 after serving as a senior director in research and development. This book is based on his experience learning about the needs of SAS customers at user events and working with SAS/STAT developers to meet those needs. Bob received a PhD in statistics from the University of North Carolina at Chapel Hill and was a research statistician at General Motors Research Laboratories before joining SAS. He is a Fellow of the American Statistical Association and received the ASA Founders Award in 2009.