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NAEP Weighting Procedures → 2002 Weighting Procedures and Variance Estimation → State Assessment Weights → Quality Assurance for State NAEP 2002 Weighting → Weighted Enrollment Checks from the State NAEP 2002 School Samples

NAEP Technical DocumentationWeighted Enrollment Checks from the State NAEP 2002 School Samples

The school sample is a probability sample from the frame, with separate samples taken for public schools within each state or jurisdiction, and private schools. The summation of the probability-weighted estimated grade enrollment aggregations (estimated grade enrollment divided by the school probability of selection) provides unbiased estimates of the corresponding frame grade enrollment information. Aggregations were computed for percent Black, Hispanic, Asian/Pacific Islander, and American Indian student enrollment, and for type of location, by state or jurisdiction, for public schools and for private schools as a whole. The mean across schools, weighted by enrollment, of the median household income of the area where the school is located, was also computed. Aggregations were also computed for state achievement data in those states for which  this data was available.

American Samoa participated for only the eighth grade. Since all eligible schools were included in the sample for the jurisdictions of Delaware, District of Columbia, Department of Defense schools (international and domestic), Guam, and Virgin Islands, their standard errors were zero. There are, in fact, differences between the sample and frame values for these jurisdictions, reflecting some updating in the estimated grade enrollment (the school's self-reported value replaces the frame value). Finally, all eligible schools were included in the sample for Hawaii and Rhode Island only in the eighth grade, but not the fourth grade.

For the fourth grade, there was little evidence of any anomalies in the samples for any jurisdictions. There was a significant difference in the estimated sample achievement mean (24) and the frame achievement mean (21) for Illinois, but none of the other characteristics showed differences and the cause is not clear. For private schools, the percentage of Hispanic students enrolled in school was significantly higher in the sample than on the frame (8.3 percent on the frame and 10.7 percent in the sample).

For the eighth grade Black students enrolled in public schools, the overall percentage for all public schools was a percentage point smaller in the sample than the frame, which was significant (16.3 percent in frame and 15.3 percent in the sample). Black student enrollment in Kentucky also appears to be lower in the sample as compared with the frame (7.8 percent in the sample versus 10.1 percent for the frame—a significant difference). The type of location was also 0.22 points higher for the sample, suggesting a larger representation of rural schools. Illinois also registered a higher achievement mean in the sample as compared to the frame, as well as a higher median income.

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