This text offers a concept-based approach with each chapter organized into discrete learning units or modules. This approach helps students focus on one topic at a time within the context of a larger chapter structure. Concept-signaling, a unique pedagogy embedded within a complete learning system, introduces students to the same concept in a number of different ways--through figures, charts, or marginal inserts--in addition to an explanation integrated into the text. Within each unit, in-text tools help them encode, retain, and recall complex information. Each unit contains a number of learning tools, such as "Key Concepts" that help students identify and recall the main issues in each module; "Survey Questions" to test and reinforce learning in the chapter summary; "Concept Charts" to summarize and review material visually to provide a relational connection; "Think About It" features that pose thought-provoking questions to sharpen critical-thinking skills; and "Try This Out " features that offer service learning suggestions, self-assessment questionnaires, and hands-on activities. "Review It" and "Recall It" sections at the end of each module ensure that students take the time to review the material and test their knowledge by completing a short quiz.