Special education is now an established part of public education in the United States—by law and by custom. However, it is still widely misunderstood and continues to be dogged by controversies related to such things as categorization, grouping, assessment, placement, funding, instruction, and a variety of legal issues. The purpose of this 13-part, 57-chapter handbook is to help profile and bring greater clarity to this sprawling and growing field. To ensure consistency across the volume, chapter authors review and integrate existing research, identify strengths and weaknesses, note gaps in the literature, and discuss implications for practice and future research. Key features include: Comprehensive Coverage—Fifty-seven chapters cover all aspects of special education in the United States including cultural and international comparisons. Issues & Trends—In addition to synthesizing empirical findings and providing a critical analysis of the status and direction of current research, chapter authors discuss issues related to practice and reflect on trends in thinking. Categorical Chapters—In order to provide a comprehensive and comparative treatment of the twelve categorical chapters in section IV, chapter authors were asked to follow a consistent outline: Definition, Causal Factors, Identification, Behavioral Characteristics, Assessment, Educational Programming, and Trends and Issues. Expertise—Edited by two of the most accomplished scholars in special education, chapter authors include a carefully chosen mixture of established and rising young stars in the field. This book is an appropriate reference volume for anyone (researchers, scholars, graduate students, practitioners, policy makers, and parents) interested in the state of special education today: its research base, current issues and practices, and future trends. It is also appropriate as a textbook for graduate level courses in special education.