Special education students often learn about the characteristics of disabilities but can lack an understanding of the relationship between diagnostic assessment and eligibility for special education services. This book focuses on the role that assessment plays in the diagnosis of a disability, determination of eligibility for special education services, and education of students with disabilities to provide a meaningful interconnection between assessment concepts and classroom application for teachers. The authors want to ensure that future special education teachers have the preparation to provide comprehensive instruction to P-12 students through this text. While special education teachers are often not the ones conducting comprehensive evaluations, it is paramount that they understand their students' individual characteristics and understand how assessment is used to determine diagnosis and eligibility. Framing the text around The Individuals with Disabilities Act (IDEA) provides students with concrete standards by which all disabilities are evaluated and regulated in our public educational system. Part I introduces the basic topics of assessment, ethics, and assessment types. Part II moves on to provide diagnostic and eligibility criteria according to IDEA categories that are most commonly diagnosed in an educational setting while Part III describes the criteria for IDEA categories most commonly diagnosed in a medical setting. Features like case studies and sample comprehensive evaluations help bring to life assessment and how it applies in real classrooms.