This is a statistics book for readers interested in ideas rather than technique. It presents, in a non-technical form, the most important statistical concepts as they are applied in public policy, the human sciences, and everyday life. It is designed to give non-mathematical readers critical insight into the uses and misuses of numbers and quantitative arguments, which are increasingly prevalent in fields ranging from sociology to medicine to literary analysis. The goal is not to train statisticians, but to present statistics as a useful tool for clear thinking in personal and professional life. The third edition has been revised and updated, placing more emphasis on giving students hands-on experience with data. Chapters 4 and 5 have been reorganized into a more logical arrangement. Many new examples and exercises have been added.