The NAEP 2006 sample design yielded a nationally representative sample of public school students in each of grades 4, 8, and 12 through a three-stage approach: selection of primary sampling units (PSUs), selection of schools within strata, and selection of students within schools. The sample of schools was selected with probability proportional to a measure of size based on the estimated grade-specific enrollment in the schools.
The 2006 sampling plan was designed to assess
within the NAEP public school samples.
These students were allocated among four different tests at grades 4 and 12, and five different tests at grade 8. The operational tests were in civics, economics (grade 12 only), and U.S. history. The field tests were in reading and mathematics, both at grades 4 and 8 only. A pilot test in writing was conducted at grades 8 and 12 only. Target sample sizes were adjusted for expected school and student response and eligibility.
As in past assessments, Black and Hispanic students were oversampled at a moderate rate. Schools in a high Black/Hispanic stratum (i.e., schools with 15 percent or more Black and Hispanic students and at least 10 Black or Hispanic students in the sample grade) were sampled at twice the rate as schools not in a high Black/Hispanic stratum to implement oversampling of Black and Hispanic students.
From the stratified frame of public schools for each grade, a systematic random sample of grade-eligible schools was drawn with probability proportional to a measure of size based on the estimated grade-specific enrollment of the school.
Each selected school in the public school sample provided a list of eligible enrolled students from which a systematic, equal probability sample of students was drawn.