AFTER years of talk about setting national standards of learning for the nation's public schools, it appears the country may be a bit closer to getting them. The board of the federally funded National Assessment of Educational Progress (NAEP) - those folks who have brought the bad news in recent years of students' poor performance in everything from math to writing ability - is ready to design national tests based on commonly agreed standards of what students should know and be able to do. At present, most tests are graded on a curve that skews performance figures. Thus, nearly every state claims its students perform above a mythical ``national average'' - a statistical impossibility. A new NAEP test would provide more objective criteria. It would also make clearly defined demands - now lacking - in the hopes that a rising educational tide would lift all boats. In theory, the idea of national standards could be a benefit. In practice, it will probably be a mixed blessing. Linking higher standards to a test is tricky. Whether or not NAEP intends it, teaching to tests in class often leads to rote learning. Tests are also a ready-made panacea for politicians - an invitation to forget about other school problems. Yet higher standards, even by means of a test, ought to be cautiously supported. This assumes that at every step along the way local control of education policy is affirmed and practiced. If teachers are already teaching to a test, why not have them teach to a good one? On the other hand, if a school is already doing well, if it already has a clear identity and a strong philosophy of learning, there is no reason to change it. Higher standards of learning do not need to clash with the idea of teaching for creativity and critical thinking. This is a concern. Again, it is something that enlightened state and local policymakers, school boards, and parents need to guard against. If done well, higher standards can lead to the staking out of a broad area of common culture in America that students should know about in order to intelligently participate in - and question - American life. NAEP makes a final decision in March.