Table of Contents  |  Search Technical Documentation  |  References

NAEP Weighting Procedures → 2002 Weighting Procedures and Variance Estimation → National Main Assessment Weights → Calculation of Replicate Weights → Poststratification of Student Replicate Weights

NAEP Technical DocumentationPoststratification of Student Replicate Weights

The poststratification process was fully replicated. The poststratification process for the sample weights is described in Poststratification of Student Weights. Applying the poststratification adjustment to the replicate weights guaranteed that the replicate standard errors will correctly incorporate the variance changes arising from poststratification. The replicate factors are as follows for the reading and writing assessments respectively (for control cell h and replicate weight r):

where

• A_h is the control total for control cell h;

• A_h(re) are the assessed reading students for control cell h;

• A_h(wr) are the assessed writing students for control cell h;

• A_h(ex) are the excluded students for control cell h;

• SUBJADJ_sk is the subject assignment weighting factor for student sk (see Poststratification of Student Weights);

• STUWGT_sk(r) is the replicate student base weight (see Student Replicate Base Weights);

• STNRADJ_d(r) is the student nonresponse adjustment for student nonresponse cell d (see Student Replicate Nonresponse Adjustments); and

• TRIM_sk is the student trimming factor (see Student Trimming Factors).

The final student weights W_sk and final student replicate weights W_sk(r), r = 1,..,62 are equal to the following for operational reading assessment and operational writing assessment students, respectively:

For the twelfth-grade students, a student in the twelfth-grade complement set (18 years or older on October 1, 2001) received the poststratification adjustment for cell h as defined by their race/ethnicity and region, even though these students were not included in the computation of the factor. For excluded students, the final weights were different depending on whether the record for the excluded student is on the operational reading assessment file or on the operational writing assessment file. The excluded student weights can be written as:

where the "o" superscript for PSFAC is equal to "re" for the reading assessment file and equal to "wr" for the writing assessment file.

Printer-friendly Version