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NAEP Weighting Procedures → 2002 Weighting Procedures and Variance Estimation → State Assessment Weights → Computation of Base Weights → Computation of Student Base Weights

NAEP Technical DocumentationStudent Base Weights

The student base weight was assigned to every student sampled to receive a 2002 reading or writing assessment, whether or not the assessment took place. The student base weight, in a sense, reflects the number of students that the sampled student represents in the population for purposes of estimation. The summation of the student base weights over a particular student group is an estimator of the total number of students in that group in the population.

The student base weight STUWGT_sk (school s, student k) was a product of the following factors:

• the school base weight  (the inverse of the school's probability of selection);

• the school nonresponse adjustment factor SNRADJ_s (see Computation of School Nonresponse Adjustments);

• the substitution adjustment, SUBADJ_s (see Computation of Base Weights for Substitute Schools);

• the school trimming adjustment TRIM_s (see Computation of Base Weights for New Schools);

• the within-school sampling interval for student selection WINSCHL_s (the within-school sampling interval is the inverse of the student sampling rate in the school); and

• a factor for year-round schools YRRND_s (see year-round school factor).

To summarize:

STUWGT_sk =  * SNRADJ_c * SUBADJ_s * TRIM_s * WINSCHL_s * YRRND_s

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