Sample 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 2011 NAEP assessments at grades 4 and 8.

The samples of AI/AN students participating in the 201 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 are reported for the same 12 states. While 6 of the 12 states had sufficient AI/AN students without oversampled, schools in 6 states were oversampled in 2011: Arizona, Minnesota, North Carolina, Oregon, Utah, and Washington.

To maximize student sample sizes, all fourth- and eighth-grade AI/AN students who were assessed in reading or mathematics, eighth-grade AI/AN students in the sampled schools who participated in the NAEP science assessment (which was administered only at grade 8 in 2011) were also selected to participate in the NIES survey. Including the students assessed in science increased the NIES survey sample by roughly 2,600 AI/AN eighth-graders without having to sample additional schools. Nonetheless, the NIES questionnaires were designed to collect information about AI/AN students' experiences in reading/language arts and mathematics, not science. Therefore, all students participating in the NIES survey completed the same questionnaires regardless of the NAEP subject area in which they were assessed. Furthermore, questionnaires were administered to participating students' reading/language arts and mathematics teachers to collect information specific to instructional practices in those subject areas. There was no separate questionnaire administered to science teachers.

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, wee density is defined by the proportion of AI/AN students enrolled (high density schools have 25 percent or more AI/AN students; low density schools have fewer than 25 percent).

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.

Last updated 22 May 2012 (JM)