The missing link in the debate on educational quality

America trudges back to school next week - to a public education system needing help from top to bottom:

* Top. In 1982-83 state legislatures voted the smallest funding increase in over 20 years to the nation's 3,163 colleges and universities.

* Middle. Some 30 percent of the students entering ninth grade won't graduate from the country's 22,834 high schools, according to a forthcoming Christian Science Monitor report on high schools.

* Bottom. A recent Monitor study of the relationship between education and the media noted that before the average youngster even sets foot in a classroom, he or she has logged 5,000 hours of television watching.

Such problems have not gone unnoticed. The report last spring by the National Commission on Excellence in Education, and the hue and cry over schooling by the covey of presidential hopefuls, has helped bring these issues sharply into focus. But answers remain elusive.

That is partly because, as William B. Durden observes in the July issue of Daedalus (the Journal of the American Academy of Arts and Sciences), we keep believing we can ''attain our educational objectives solely by institutional strategies'' - by reforming the schools themselves. Increasingly, however, educators realize that schools must be seen not in isolation but in context - in their many relationships to the rest of society.

What kind of relationships? Many point to the school-home link, citing the impact on education of poverty, divorce, and ebbing moral and religious training at home. Others study the link between schools and the job-market, or the computer, or the minority community. But one link has yet to be thoroughly explored: the relationships between the schools and the state legislatures.

It's a crucial link, since legislators play key roles in funding the nation's schools. But lawmakers are frequently underpaid, often overworked, and regularly swamped with more issues than they can manage. Look, for instance, at the region where public education began - New England. In Rhode Island, lawmakers are paid $5 per day. Next door in Massachusetts they average $30,000 a year - but tackle more bills per session (8,650 in 1982) than any other legislature in the nation. Staff support is often minimal. Yet the policy questions they confront - from property-tax exemptions for educational institutions to entrance requirements for minority students - are profound.

That's why a soon-to-be-announced program by the New England Board of Higher Education (NEBHE, a nonprofit agency funded by the six states in the region) bears watching. The plan calls for educators to work closely with lawmakers to increase their understanding of educational issues. Under a grant awarded through the Fund for the Improvement of Post-Secondary Education by the US Department of Education, NEBHE will shortly kick off a three-year program of seminars, briefings, and specially designed publications for the region's 1,323 legislators.

Admittedly, the plan is limited. It only focuses on one link, between education and the legislature. It covers only one region (New England), and only one band of the educational spectrum (higher education). And it zeroes in on a part of the problem guaranteed to interest politicians: the relationship between support for public higher education in New England (which has been dismal) and the region's economic development (which depends on a continuing influx of college graduates).

Within these boundaries, however, program director Melvin Bernstein thinks the idea (the first of its kind in the nation) can help determine ''what legislators know, what they feel they need to know and how we can best help them understand the financial condition and significance of higher education in the economy.''

If his educate-the-lawmakers plan works for higher education in New England, it should work elsewhere and on other levels. One thing is certain: If the nation's public education is to improve, the men and women who vote to fund it need an informed analysis of the issues before them. That's not all the schools need. But it's an excellent beginning.