OPINION polls routinely find the quality of American education to be a matter of grave concern among the public.  For example, a September 1996, Washington Post poll found that over 60 percent of its respondents worried “a great deal” that the educational system will get worse. That the public had reason to be worried was confirmed at almost the same time by the release of a report by a national commission calling teacher standards “a national shame.” And, if polls and reports were not enough to convince us that this is a genuine concern, we need only to observe the numerous books published each year criticizing the educational system. Reform proposals, of course, are not lacking, but they seem to have the same ethereal quality that we associate with good-government reforms.  Both are such complex entities that it is difficult to figure out what to do first.