A sample of schools and students is selected to represent the state. In an average state, 2,500 students in approximately 100 schools are selected per grade, per subject assessed.
The selection of schools is random, within classes of schools with similar characteristics. But some schools or groups of schools (districts) can be selected for each cycle if they are unique in the state. For instance, a district may be in the only major metropolitan area of a state or have the majority of a minority population in the state.
Typically, thirty students per subject per grade are selected randomly in each school. Some of the students who are randomly selected are classified as students with disabilities (SD) or as limited-English proficient (LEP) students. NAEP's goal is to assess all students in the sample, and will assess these students if at all possible. To read more, see the full description of accommodations issues.
See some of the most frequently asked questions about the state sample design.