This Fourth Edition provides tools for the rigorous and critical analysis of experimental data. Assuming only basic mathematical skills, the book provides a complete and exhaustive introduction to the statistical methods available and updates all material to cover current practices. The book also provides three entirely new and up-to-the-minute chapters. One provides the first practical guide to performing meta analysis allowing for using the power inherent in multiple similar studies; two others cover Bayesian analysis and data analysis in pharmacology, which discuss analysis of receptor binding assays, safety pharmacology assays, and other standard study types conducted in pharmacology.