Given the complexity of the weighting procedures utilized in NAEP, a range of quality control (QC) checks was conducted throughout the weighting process to identify potential problems with collected student-level demographic data or with specific weighting procedures. The QC processes included:
To validate the weighting process, extensive tabulations of various school and student characteristics at different stages of the process were conducted. At school level the analyses were performed within high and low grades relative to the students' age. The school level characteristics included in the tabulations were minority enrollment, 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 grade, free/reduced lunch program participation status, Title 1 status, students with disability (SD) status, and English language learners (ELL) status.