Click the "Appendix B: Technical Notes" bookmark in:
The Status of Public and Private School Library Media Centers in the United States, 1999-2000 (611 KB)
The sample of school library media centers surveyed consists of 10,600 public school libraries and 300 public charter school libraries in the United States.
NCES, with the assistance of the U.S. Census Bureau, conducts the School Library Media Centers Survey as part of the Schools and Staffing Survey (SASS).
This survey is used to assess the status of school library media centers, nationwide.