as well as to solve problems and communicate their thinking and reasoning to others. However, the nationally developed standards deliberately leave specific curricular decisions to state and local officials.

The NCTM, NRC, and ITEA standards call for changes not only in what students learn, but also in how that content is taught. According to the standards documents, teachers should have deep understanding of the science, mathematics, and technology content they teach; recognize and address common student preconceptions; design classroom experiences that actively engage students in building their understanding; emphasize the use and application of what is learned; and use assessment as an integral part of instruction.

While standards provide a vision for teaching and learning, the vision cannot be realized unless the standards permeate the education system. The U.S. education system is large, diverse, and complex, with many layers of governance. States play major roles in funding and regulating education. At the same time, what happens in individual classrooms is affected by decisions made in other layers of this loosely coupled system.

Based on research, interactions with practitioners in the field, and personal experiences, the authoring Committee chose three main routes or “channels” to describe paths through which reform ideas might flow to various layers of the system and might eventually influence teaching and learning. As reforms (such as standards) enter the education system, they traverse one or more of these “channels,” and thus may affect policies, programs, and practices within various jurisdictional layers. The three major channels of influence identified by the Committee are: Curriculum, Teacher Development, and Assessment and Accountability. In addition, standards may have an impact on education’s social and political