Skip Navigation

Computation of Full-Sample Weights for the 2008 LTT Assessment



Computation of Base Weights

School and Student Nonresponse Adjustments

School and Student Weight Trimming Adjustments

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 age (9, 13, 17) and subject (mathematics or reading). The full-sample student weight reflects the number of students that the sampled student represents in the population 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 in 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 for school and student nonresponse, and school and student trimming. The full-sample weight for student k from school s in stratum j (FSTUWGTjsk) can be expressed as follows:

FSTUWGT subscript j s k equals STU underscore BWT subscript j s k times SCH underscore NRAF subscript j s times STU underscore NRAF subscript j s k times SCH underscore TRIM subscript j s times STU underscore TRIM subscript j s k


School sampling strata for a given assessment varied by school type. See public school strata and private school strata for descriptions of the public and private school stratum definitions.

Last updated 28 September 2010 (EH)