The schools and students participating in NAEP assessments are selected to be representative of all schools nationally and of public schools at the state level. Samples of schools and students are drawn from participating states and from the District of Columbia and Department of Defense schools.
While national results reflect the performance of students in public, private, and other types of schools (i.e., Bureau of Indian Education schools and Department of Defense schools), state-level results reflect the performance of public school students only. Results are reported separately for Department of Defense schools in state tables and maps. More information on NAEP sampling can be found in the sample design section of NAEP Technical Documentation.