Given the complexity of the weighting procedures utilized in NAEP, a range of quality control (QC) processes was introduced into the weighting of the sample results, in order to identify problems, provide feedback to the process, and indicate those areas requiring both remedial and future attention. The QC processes carried out for the 2002 assessment included internal checks performed during the weighting process and external (before and after) checks of the weighting process.
The external checks of the weighting process included extensive tabulations of various school and student characteristics at different stages of the process. The school level characteristics included in the tabulations were minority enrollment, achievement scores, median income (based on the ZIP Code area in which the school is located), and type of location. At the student level, the tabulations included race/ethnicity, gender, relative age, and SD/LEP status.