National Indian Education StudySample Design and Weighting

The schools and students participating in NAEP assessments are selected to be representative of the target population of all fourth- and eighth-grade American Indian/Alaska Native (AI/AN) students in the United States attending public, Bureau of Indian Education (BIE), Department of Defense, and private schools. The sample selection for NIES took place in conjunction with the sampling activities for the 2019 NAEP assessments at grades 4 and 8.

The samples of AI/AN students participating in the 2019 NAEP reading and mathematics assessments, upon which the student performance results are based, represent augmentations of the sample of AI/AN students who would usually be selected to participate in NAEP. This allows more detailed reporting of performance for this group.

In 2005, seven states had sufficient samples of AI/AN students to report state-level data. In 2007, a total of 11 states had sufficiently large samples, with Minnesota, North Carolina, Oregon, and Washington being added to the original seven selected states for 2005. In 2009, results were also reported for Utah, resulting in state-level reporting for a total of 12 states. In 2011, results were reported for the same 12 states. While 6 of the 12 states had sufficient AI/AN students without being oversampled, schools in 6 states were oversampled in 2011: Arizona, Minnesota, North Carolina, Oregon, Utah, and Washington. In 2015, fourteen states had sufficient samples of AI/AN students to report state-level data. Schools in seven of these states (Alaska, Montana, New Mexico, North Dakota, Oklahoma, South Dakota, and Wyoming) had sufficient AI/AN students to report results without oversampling, while schools in the other seven states (Arizona, Minnesota, North Carolina, Oregon, Utah, Washington, and Wisconsin) were oversampled in 2015. In 2019, results were reported for 15 states, with Nebraska being added in 2019. While samples of AI/AN students were large enough to report performance results in 15 states in 2019, in a few cases, not all states had large enough samples to report results for both reading and mathematics at grades 4 and 8. Schools in 8 of these states with high proportions of AI/AN students were oversampled in 2019: Arizona, Minnesota, Nebraska, North Carolina, Oregon, Utah, Washington, and Wisconsin.

To maximize student sample sizes, all fourth- and eighth-grade AI/AN students in the sampled schools were selected for participation in the NIES survey. This means that, in addition to the fourth- and eighth-grade AI/AN students who were assessed in mathematics and reading in 2019, AI/AN students in the sampled schools who participated in the NAEP mathematics multi-stage testing (MST) special study were also selected to participate in the NIES survey. Including the students assessed in MST increased the NIES survey sample by roughly 700 AI/AN fourth-graders and 600 AI/AN eighth-graders without having to sample additional schools. All students participating in the NIES survey completed the same grade-specific questionnaire regardless of the NAEP subject area in which they were assessed. Furthermore, questionnaires were administered to participating students' mathematics and reading/language arts teachers to collect information specific to instructional practices in those subject areas.

Samples were obtained to not only be representative of all AI/AN students in the United States at grades 4 and 8, but also to allow comparisons between AI/AN students attending BIE schools and high density and low density public schools. Density is defined by the proportion of AI/AN students enrolled. High density schools have 25 percent or more AI/AN students; low density public schools have fewer than 25 percent AI/AN students.

The oversampling of schools with high proportions of AI/AN students was accounted for by the sampling weights. The general purpose of weighting is to adjust for the unequal probabilities of selection of schools and students, and to adjust for the effects of nonresponse by schools and students selected to participate.