​​NAEP Technical DocumentationComputation of Full-Sample Student Weights

			Computation of Base Weights School and Student Nonresponse Weight Adjustments School and Student Weight Trimming Adjustments Student Weight Raking Adjustment

The full-sample or final student weight is the sampling weight used to derive NAEP student estimates of population and subpopulation characteristics for a specified grade (4 or 8) or age (9 or 13) and assessment subject (civics, mathematics, reading, or U.S. history). The full-sample student weight reflects the number of students in the population that the sampled student represents for purposes of estimation. The summation of the final student weights over a particular student group provides an estimate of the total number of students in that group within the population.

The full-sample weight, which is used to produce survey estimates, is distinct from a replicate weight that is used to estimate variances of survey estimates. The full-sample weight is assigned to participating students and reflects the student base weight after the application of the various weighting adjustments. The full-sample weight \(FSTUWGT_{jsk}\) for student \(k\) from school \(s\) in stratum \(j\) can be expressed as

\begin{equation} FSTUWGT_{jsk} = STU\_BWT_{jsk} \times SCH\_NRAF_{js} \times STU\_NRAF_{jsk} \times \\ SCH\_TRIM_{js} \times STU\_TRIM_{jsk} \times STU\_RAKE_{jsk} , \end{equation}

where

• \(STU\_BWT_{jsk}\) is the student base weight;
  

• \(SCH\_NRAF_{js}\) is the school-level nonresponse adjustment factor;

• \(STU\_NRAF_{jsk}\) is the student-level nonresponse adjustment factor;

• \(SCH\_TRIM_{js}\) is the school-level weight trimming adjustment factor;

• \(STU\_TRIM_{jsk}\) is the student-level weight trimming adjustment factor; and

• \(STU\_RAKE_{jsk}\) is the student-level raking adjustment factor.

School sampling strata for a given assessment vary by school type (public or private), assessment subject (civics, mathematics, reading,​ or U.S. history), and grade (4 or 8) or age (9 or 13). See the links below for descriptions of the school strata for the various assessments.

• State public school samples for mathematics and reading at grades 4 and 8
• National private school samples for mathematics and reading at grades 4 and 8
• National public school samples for civics and U.S. history at grade 8
• National private school samples for civics and U.S. history at grade 8
• National public school samples for mathematics and reading at ages 9 and 13
• National private school samples for mathematics and reading at ages 9 and 13​

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