NAEP assesses representative samples of students rather than the entire student population. The sample selection process utilizes a probability sample design. In this type of sample, each school and each student has a known probability of being selected. Samples are selected according to a multistage design, with students drawn from within sampled public and private schools nationwide. The school probabilities are proportional to the estimated number of students in the grade assessed.Learn More
The Common Core of Data (CCD) file serves as the sampling frame for the selection of public schools in each state/jurisdiction. The CCD is a comprehensive list of operating public schools in each jurisdiction that is compiled each school year by the National Center for Education Statistics (NCES). The sample of students in districts participating in TUDA represents an augmentation of the sample of students selected as part of the state samples. All students at more local geographic sampling levels also make up part of the broader samples. For example, the TUDA samples are included as part of the corresponding state samples, just as the state samples are included as part of the national sample.
The Private School Survey (PSS) is a survey of all U.S. private schools carried out biennially by the Census Bureau under contract to NCES. The PSS serves as the sampling frame for private schools. While state and district results are based on samples of public schools only, the national results are based on the combined samples of both public and private schools.
Because the schools and students who participate in the assessment represent only a portion of the larger population of interest, the assessment results are weighted to make appropriate inferences about the populations from the student, school, and district samples. Sampling weights are adjusted to account for the disproportionate representation of some groups in the selected sample. This includes oversampling of schools with high concentrations of students from certain racial/ethnic groups and the lower sampling rates of students who attend very small schools.
Within each selected school and grade to be assessed, students from the selected grade (4, 8, or 12) are chosen at random to participate in NAEP for up to two subjects. Every student has a chance of being chosen--regardless of race/ethnicity, socioeconomic status, disability, status as an English language learner, or any other factors.
Results are never reported for individual students. National results are reported for all assessment subjects. Mathematics, reading (and sometimes science and writing) results are also reported at the state level and for participating urban districts. Both public and private schools results are reported for the nation, but only public school results are reported at the state level.
Students in a given assessment session will take a variety of different assessment forms, generally across several subjects. Individual students only complete a subset of NAEP items within each subject area.
A technique called Balanced Incomplete Block (BIB) spiraling is used in which groups of items are systematically arranged with other groups of items within test forms to assure that the entire content domain for the subject is covered. And all items are completed by a representative sample of students, though individual students only complete a fraction of the items.Learn More