The schools and students participating in NAEP assessments are selected to be representative of all schools nationally. The results from the assessed students are combined to provide accurate estimates of the overall performance of students in public, private, and other types of schools (i.e., Bureau of Indian Education schools and Department of Defense schools) in the nation. The sample sizes shown here give the numbers of students selected to participate, not the numbers who actually did participate. See the participation rates for this assessment.
More information on sampling can be found in NAEP Technical Documentation.