Written with the data analyst in mind and based on a course taught at the University of Washington, this volume answers key practical questions professionals typically encounter, such as which data analysis method to use and how to interpret and communicate results. Starting by looking at the desired outcome, this book then works backwards. It gives guidance on ways to communicate the results of analyses, and then covers the formulation of scientific questions, before tackling study design, and statistical modeling with emphasis on ways to deal with assumptions. The book is full of examples that use real data and gives software suggestions in an appendix.