The National Assessment of Educational Progress
(NAEP) is the largest nationally representative and continuing assessment of
what America's students know and can do in various subject areas. Assessments
are conducted periodically in mathematics, reading, science, writing, the arts,
civics, economics, geography, and U.S. history.
Since NAEP assessments are administered uniformly using the
same sets of test booklets across the nation, NAEP results serve as a common
metric for all states and selected urban districts. The assessment stays
essentially the same from year to year, with only carefully documented changes.
This permits NAEP to provide a clear picture of student academic progress over
Link: NAEP statistics