Why do students from France or Germany work harder than our kids? They have the same distractions as American students. They have TV sets and pop culture.

A few weeks ago, I saw a TV interview with some Russian youngsters who now live in the U.S. After some standard questions, the interviewer asked them to compare their school experiences here with their experiences in Russia. Every one of these seventh and eighth graders had the same response: They'd already learned the material they were getting in our seventh and eighth grade classes when they were in third and fourth grade in Russia. They said that school in the U.S. was very easy.

There was nothing unusual about this exchange. Indeed, most people who have met foreign students from France or Germany or Japan have heard the same things. And if we question students like these a little further, we find that they are far ahead of their US counterparts because they are assigned more work and more challenging work, and they work harder to get it all done. But why do they work harder? They have the same distractions as American kids. They have TV sets and pop culture.

One of the main reasons is that these other countries have national curriculums. They have decided what students need to know and be able to do by the time they graduate from secondary school. And they've worked back from these goals to figure out what children should learn by the time they are ages 14 and 9.

That's not true in the U.S. Our 50 state governments have developed curriculum materials, but they are very broadly defined. So each school or teacher can select from this broad array and develop what amounts to an individual curriculum.

This makes for plenty of variety but very little continuity. As a result, students who move from one school -- or even one class -- to another often find they are out of sync because they have not studied the math or history on which the coming year's work will be based. In countries where there is a national curriculum, fewer students are lost -- and fewer teachers are lost because they know what the students who walk into their classroom have already studied.

A national curriculum gives everyone involved -- students, parents and teachers -- a different perspective on schoolwork. In the U.S., when a teacher piles on the work, students are likely to object. They say it's too hard and too much, and they complain that other teachers or other schools don't expect that kind of work. Often parents support these objections. So there is a process of negotiation about schoolwork in which students, and frequently parents, play a big role.

Sometimes teachers don't ask enough of students. They feel sorry for some youngsters because of their socioeconomic or racial or ethnic background and decide they won't be able to do real work. So they teach a watered-down curriculum and shortchange youngsters who could learn if they were given a chance.

In our system, how much work students do in a given class is up for grabs. Sometimes it's determined by the willingness or resistance of students and parents. Sometimes it's based on the teacher's expectations. In any case, the level and amount of work common in countries with national curriculums is practically never reached here. The choices our system allows inevitably lead to softer standards and less work just as the mandates in other countries lead to more work and much higher levels of achievement. If a student or a parent in one of these countries does complain, the teacher says, "All the other third-grade youngsters are doing this work, and you can, too." And the teacher probably reminds the parents and child that falling behind now can lead to serious consequences later -- like not passing an important exam.

Learning to write well or be competent in math is a lot like preparing for the Olympics. Youngsters have to work hard and do more than they think they can. This can be unpleasant and even border on the painful, but it takes this kind of stretching to achieve high levels in any field. In the U.S., a teacher who pushes students to work hard is viewed as unreasonable or even mean. But where there are external standards, a teacher is more like a coach -- someone who is helping prepare kids for the Olympics -- than like someone who has odd, personal ideas about education.

With a national curriculum, everybody knows what is required. If there also are clear and visible stakes -- getting into university or an apprenticeship program -- the pressure is on to make sure youngsters meet the standards. Without national standards and a national curriculum there are no such pressures. That's why students in other countries work hard and do well -- and why students in our "easy" and undemanding schools do not. Knowing that should lead us to act.