The sampling frame for public schools in 2006 was derived from the Common Core of Data (CCD) file corresponding to the 2003-2004 school year. The CCD files provided the frame for all regular public, state-operated public, Bureau of Indian Education (BIE), and Department of Defense Domestic Dependent Elementary and Secondary Schools (DDESS) open during the 2003-2004 school year.
The sampling frame was restricted to schools located in the primary sampling units (PSUs) selected for NAEP 2006. In addition, the sampling frame excluded all schools that were ungraded, classified as vocational with no enrollment, provided only special education, were home school entities, were juvenile correctional institutions, or were parts of prisons or hospitals.
The following table presents the number of schools and estimated enrollment for the public school frame by grade. The unweighted estimated enrollment is restricted to the selected PSUs. The weighted estimated enrollment incorporates the PSU weight (inverse of the probability of selecting the PSU), and thus is a national estimate of the number of public school students in the grade.
|Grade||Schools||Estimated enrollment (unweighted)||Estimated enrollment (weighted)|
|SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2006.|
For quality control purposes, school and student counts from the sampling frame were compared to school and student counts from the NAEP 2005 frames. No major issues were found.