The first book that directly uses R to teach data analysis, this text focuses on the practice of regression and analysis of variance. It demonstrates the different methods available and in which situations each one applies. The book covers the basics of estimation, missing data, factorial designs, and block designs and also includes discussion on topics rarely addressed in books of this type, such as model uncertainty. The presentation incorporates examples that clarify both the use of each technique and the conclusions one can draw from the results. All of the data sets used in the book are available for download online.