Full of tools, tricks, and tips for solving problems in the real world, this book serves as an ideal training manual for those who are new to or intimidated by quantitative analysis and acts as an excellent refresher for those who have more experience but want to improve the quality of their data, the clarity of their graphics, and the cogency of their arguments. In addition to containing numerous updates to the contents -- references, URLs, and reading lists -- this second edition includes a new foreword, revised chapters, and an epilogue. Mastering the art of problem solving takes over proficiency with basic calculations; it requires understanding how people use information, recognising the importance of ideology, learning the art of storytelling, and acknowledging the important distinction between facts and values. Intended for executives, professors, and students, this guide addresses these and other essential skills.