We measure a country's success not only by the average national income but also by how many people are living in poverty. Why not apply the same criteria to education? It's important that we have kids at the very top, and we also need a broad middle range of students-the country runs on them. But there's something wrong with an education system that leaves many kids far behind.

That's what U.S. education is doing, and if we need any confirmation of how unfair and unequal our education system is, we can get it by looking at Science Achievements in Seventeen Countries (Elmsford, N. Y.: Pergamon, 1988), which reports data from the latest International Association for the Evaluation of Educational Achievement (IEA) examination of 10, 14 and 18-year-olds. The results of his exam, which have been widely reported -- and disputed -- put US. kids close to the bottom. But the IEA report contains some other equally interesting measures of educational quality that have not gotten any attention.

For example, IEA took the lowest-scoring school in the top-scoring country -- for the 14-year-old group, the country was Hungary -- and asked what percentage of schools in the other participating countries scored lower than Hungary's lowest school. According to this measure, only 1 percent of Swedish and Japanese schools and 5 percent of Korean schools fell below Hungary's worst. Schools from the Netherlands and England performed relatively poorly -- 16 percent of the Dutch and 19 percent of the English schools were worse than Hungary's worst. But their performance was great compared to ours. Thirty percent -nearly one-third- of our schools achieved at a lower level than the worst-performing Hungarian school. Among developed countries, only Italy had a poorer record.

Data about the performance of our low-scoring students were also very discouraging. Looking at the scores of the bottom 25 percent of students, only kids from the Philippines had a lower average score than U.S. students, and our kids who had the lowest scores were performing at a level that was not much above chance.

Taken together, these measures suggest that the U.S. is one or the least successful of developed nations at preventing large numbers of students from getting an inadequate education. This. may be partly a matter of financial equity. Other developed countries tend to have national education systems and therefore spend about the same amount of money per student. I'll take up this issue in a later column. But E.D. Hirsch, author of Cultural Literacy, suggests another reason.

Some people say our results are poor in comparison with Japan's or Korea's because their countries are homogeneous and ours is not. But Hirsch says that a multicultural society is no bar to achieving educational equity: Good results have more to do with whether or not a country has a curriculum that specifies a certain body of core knowledge that teachers are responsible for teaching and kids for learning. In an unpublished paper called "Fairness and Core Knowledge," Hirsch points out that Japan and Hungary, which scored well according to every measure, have such curriculums; England, which scored badly, did not, though it has since taken steps to adopt one.

Hirsch also links the success that French and German schools have with children who do not belong to the dominant culture -- and whom we would consider disadvantaged -- with their schools' emphasis on core knowledge. According to Hirsch, West German schools bring the children of Turkish "guest workers" up to grade level despite "enormous educational handicaps." And in France, the children of immigrants who are born in France and attend French schools from the beginning achieve at a slightly higher level than French children who come from similar socioeconomic backgrounds.

Why should teaching core knowledge make such a difference? And why should it be particularly helpful for disadvantaged children? The immigrant children Hirsch describes are able to compensate for differences. that might handicap them in German and French schools because the education systems have specified in detail the material that all youngsters are supposed to learn. Standards like these, Hirsch says, "enable tutors to focus on the specific knowledge that students need in order to
attain grade level." They set up clear expectations for the kids and their teachers, and they give kids a foundation oil which to build in succeeding grades.

In U.S. schools, what is studied and in what grade is still largely a matter of local choice. So schools and school districts are free to hold students up to high standards or, as often happens in the case of disadvantaged children, to decide the kids can't do the work and give them a watered-down curriculum. The trouble with this is that it virtually guarantees these children will fall behind their more advantaged peers-and never catch up. So instead of compensating for social inequalities, our schools unwittingly
help to perpetuate them.

Some people have been very critical of Hirsch's proposals on the grounds that they try to impose the dominant culture on groups that would rather have their children learn their own culture. But the thrust of Hirsch's proposal is egalitarian. He believes that by starting early and by giving all children the same core knowledge to learn, we can. prevent the creation of an educational underclass.