Writing the third edition ofPolicing in Americawas a challenge. Reactions to the first two editions from colleagues and our students were gratifying. Our original goal was to produce a book that could both serve as an introductory textbook and spur the interest and thinking of both our students and our colleagues. The comments we have received indicate that we have been successful. Instructors and students were satisfied with the level and depth of coverage, and the style of presentation. Our challenge in this edition was twofold. First, how might we improve on our earlier success? Second, how could we best incorporate the explosion of knowledge about the police? The third edition retains the best of the earlier editions and includes improvements suggested by colleagues and the latest findings from the continually expanding body of policing knowledge. We continue to use a "conversational" tone, writing in "plain English." Where we need to use precise or jargonistic terms, we define them in the text. Our purpose remains that of communicating ideas, and we still think that is best done simply. The ideas are complex, but the reading is clear. We still want readers to wrestle with the ideas, not the vocabulary or sentence structure. FRAMEWORK The third edition follows the same framework we used in the second. To organize the large and diverse body of information, we provide a conceptual framework within which we hope to understand the police. We believe that policing in practice--what the police do on the street--is a product of a number of factors or forces. We use a balance-of-forces metaphor for understanding the police and devote chapters to identifying the important forces and for illustrating ways in which different balances are reached. We recognize not only that differences exist among police agencies in the United States but also that these differences are purposeful. What works in one community may not work in another for very legitimate and understandable reasons. We don't use words such ascauseordeterminantwhen discussing factors that appear to be linked to police practice. Instead, we focus on correlates of policing--factors that may not explain any particular police action, but that do seem to explain police practices in general. In combination with our balance-of-forces metaphor, we make recurrent reference to correlates of policing in substantive chapters. This recurring topic provides unity and continuity to our examination of police practice. Our colleagues and students tell us that this framework encourages readers to develop their own integrative skills. PEDAGOGICAL FEATURES As a learning tool, this textbook is designed to assist students in learning about the police. Each chapter begins with a detailed outline of the topics included within it. As we introduce new words, we define them in the text so that readers do not have to flip through the book. To assist readers further, we have included review questions at the end of each chapter, called the "Chapter Checkup." Probably the best way to use these questions is to read them first, then read the chapter knowing what we believe readers should gain from the chapter. Upon finishing the chapter, readers should take a few moments to answer each of the questions to be sure that they have understood the material. Each chapter also contains a summary, sometimes under the heading "Correlates," and sometimes simply titled "Conclusion." We have included a detailed and exhaustive index to make it easier for readers to find specific topics. Finally, each chapter is extensively referenced and the list of references provides a solid bibliography for readers who wish to begin an independent study of any of the topics discussed in the book. We believe that the use of a recurrent theme and writing in plain English makes the book "reader friendly." Where appropriate, we have included bLangworthy, Robert H. is the author of 'Policing in America A Balance of Forces', published 2002 under ISBN 9780130926241 and ISBN 0130926248.