ABSTRACT
By definition, textbooks attempt to distill and interpret the knowledge and scholarship of a discipline. They attempt to provide an overview of a field in sufficient breadth and depth that students can begin to understand what the discipline is about, and the methodologies and scholarship that underpin it. Thus, textbooks represent what is known about a discipline, modified according to the needs, knowledge, and maturity of the anticipated audience. Textbooks, then, are a standard resource, reference, and instructional tool, and so it is not surprising that it is from these instructional materials that teachers teach and students learn. Across grade levels in U.S. schools, in subjects as diverse as American history, chemistry, and health, and at various grade levels, the likelihood is that textbooks are the primary instructional material.
