After student trimming, weighting continues in two parallel processes. Reporting weights are the result of one of these processes, and modular weights are the result of the other. Modular weights are used for analyses involving one sample type or for comparing one sample type against the other. Each sample type separately weights up to the target population. The weights are calculated for each sample type by grade and subject for the national main assessment. For example, modular weights could be used to compare the NAEP performance of limited-English-proficient (LEP) students in the S2 sample with the performance of LEP students in the S3 sample.
Modular weights differ from reporting weights in two ways: