The NAEP sampling and weighting staff generated final sample weights and replicate weights for the 2002 assessment. There were three components to the assessment:
the national main assessment in reading and writing;
the state assessment in reading and writing, which includes the Trial Urban District Assessment (TUDA) samples; and
the bridge studies.
In years prior to 2002, separate samples were drawn for the state assessment and for the national assessment for public schools grades 4 and 8. In 2002 for the first time the same sample of schools and students in public schools grades 4 and 8 were used for both the state assessment and for the national assessment in jurisdictions which chose to participate in the state assessment. The same sets of weights were used then for both studies when this overlap occurred. These weights are described only on the state assessment weights pages, and thus these pages are the correct pages to refer to for the national assessment weights in these overlapping samples. The national main assessment also includes fourth and eighth grade public school students in jurisdictions that did not participate in the state assessment, twelfth grade public school students, and private school students. The national main assessment pages only describe the weighting methodology for these non-overlapping parts of the national main assessment sample.