The NAEP 2007 state operational mathematics and reading assessments covered fourth- and eighth-grade students, and writing for eighth-grade students, in public schools for each subject, referred to as the Alpha sample. A representative sample of public school students was drawn in each participating jurisdiction, including states, the District of Columbia, Puerto Rico, Bureau of Indian Education (BIE) schools, Department of Defense (DoD) schools and in school districts chosen for the Trial Urban District Assessment (TUDA) study.
Jurisdiction participation in the mathematics and reading assessments was mandatory, whereas participation in the writing study was optional, with six jurisdictions declining to participate. By design, Puerto Rico participated only in the mathematics state assessment and the BIE schools participated in reading and mathematics only.
Each jurisdiction sample was designed to produce aggregate estimates with approximately equal precision for all the participating jurisdictions, as well as estimates for various subpopulations of interest. The target student sample size per jurisdiction for an operational assessment was 3,150 students. In fourth grade, the total sample size for a jurisdiction was 6,500, which included reading and mathematics assessments, as well as 200 pilot tests. In eighth grade, the total sample size for a jurisdiction that was participating in writing assessment was 9,750, which included reading, mathematics, and writing assessments and 300 pilot tests. Jurisdictions not participating in the state writing assessment had a target sample size of 6,650, which included reading and mathematics assessments and 350 writing students sampled for the national writing sample. No students were sampled for the pilot test in states that did not participate in writing.
The target population for the NAEP 2007 state assessment included students in public schools who were enrolled in the fourth and eighth grades at the time of assessment. The sampling frame included public schools having the relevant grade in each jurisdiction. The samples were selected based on a two-stage sample design:
From the stratified frame of public schools for each grade within each jurisdiction, 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.
For the TUDA study, additional schools were sampled from the 10 participating TUDA districts at the same time schools were selected for the jurisdiction samples. The TUDA districts were as follows:
These subsamples affected the design of the state samples in those states where TUDA districts were oversampled. In each of these states, there were distinct sampling rates for each TUDA district and for the rest of the state.
Sample sizes were increased in three large states (California, Florida, Texas) in recognition of their diverse populations because increased sample sizes permit meaningful breakdowns of the results at finer levels. Applying increases in these larges states also significantly improves the precision of national estimates, both overall and by demographic groups.
Each selected school provided a list of eligible enrolled students from which a systematic sample of students was drawn. In fourth grade, 62 students, where possible, were taken from each school, half for mathematics and half for reading. In eighth-grade schools that did not participate in the state writing sample, 63 students, if possible, were taken from each school, 30 for mathematics, 30 for reading, and 3 for writing. In eighth-grade schools that did participate in the state writing assessment, 93 students, if possible, were taken from each school, one-third for each of the three subjects.