Common Core of Data
The Common Core of Data (CCD) is the Department of Education's primary database on public elementary and secondary education in the U.S. CCD is a comprehensive, annual, national statistical database of all public elementary and secondary schools and school districts, which contains data that are designed to be comparable across states. The objectives of CCD are (1) to provide an official listing of public elementary and secondary schools and school districts in the nation, which can be used to select samples for other National Center for Education Statistics (NCES) surveys, and (2) to provide basic information and descriptive statistics on public elementary and secondary schools and schooling in general.
CCD is made up of a set of five surveys sent to state education departments. Most of the data are obtained from administrative records maintained by the state education agencies. Statistical information is collected annually from schools and school districts (including supervisory unions and regional education service agencies) in the 50 states, the District of Columbia, Department of Defense Schools, and the outlying areas. State education agencies compile the data in prescribed formats and transmit the information to NCES.
Approximately 100,000 public elementary and secondary schools and 18,000 public school districts participate in the survey. Reporting of high school completion rates varies by state as well as by sociodemographic group. For more information on response rates see Public School Graduates and Dropouts From the Common Core of Data: School Year 2007–08 - Appendix A: Methodology and Technical Note.
National Center for Education Statistics Common Core of Data and related web pages.