The education system in the United States is continually challenged to adapt and improve, in part because its mission has become far more ambitious than it once was. At the turn of the 20th century, less than one-tenth of students enrolled were expected to graduate from high school. Today, most people expect schools to prepare all students to succeed in postsecondary education and to prosper in a complex, fast-changing global economy. Goals have broadened to include not only rigorous benchmarks in core academic subjects, but also technological literacy and the subtler capacities known as 21st-century skills. To identify the most important measures for education and other issues and provide quality data on them to the American people, Congress authorized the creation of a Key National Indicators System (KNIS). This system will be a single Web-based information source designed to help policy makers and the public better assess the position and progress of the nation across a wide range of areas. Identifying the right set of indicators for each area is not a small challenge. To serve their purpose of providing objective information that can encourage improvement and innovation, the indicators need to be valid and reliable but they also need to capture the report committee's aspirations for education. This report describes a workshop, planned under the aegis of the Board on Testing and Assessment and the Committee on National Statistics of the National Research Council. "Key National Education Indicators" is a summary of the meeting of a group with extensive experience in research, public policy, and practice. The goal of the workshop was not to make a final selection of indicators, but to take an important first step by clearly identifying the parameters of the challenge.