Revision with unchanged content. Understanding statistical inference-the practice of making a generalization from a sample to a larger population-is increasingly important in our information age and emerging global economy. Indeed, citizens increasingly need to interpret information obtained from samples, and to understand and assess claims about intended populations made on the basis of such information. For instance, results of public opinion polls, and reports of the effectiveness of drug treatments, to name just two, often make implied claims about intended underlying populations on the basis of statistical data obtained through sampling. But what might it mean to have a coherent understanding of statistical inference? Further, what might be entailed in developing such understanding? This book addresses these questions by reporting on an empirical study involving high school students. The study investigates the emergence of students' thinking as they participated in a classroom instructional experiment designed to support them in exploring the deep structure of statistical inference. The book is relevant for educational researchers, teachers, and other professionals interested in statistics learning and instruction.