JUDY WOODRUFF: Next: how the American education system stacks up in global rankings and the questions surrounding that assessment.

Jeffrey Brown has the story.

WOMAN: You got it. You got it. Good. Good. Good. Good.

JEFFREY BROWN: It's considered by many the world's most important exam. The Program for International Student Assessment, or PISA test, has been given to 15-year-olds in 65 countries and educational systems every three years since 2000, a way to test and compare performances in reading, math and science, with an emphasis on how facts and figures can be not just learned, but used.

Results from 2012 were released today, and, once again, the U.S. hovered near the middle of the pack, lagging in some areas, even as other countries advanced. Math remains the biggest challenge; 29 other systems had higher average scores than American high schoolers.

The U.S. fared better in reading, where it ranked 20th, and in science, ranking 23rd. The best results were in East Asia, where students from Shanghai, Singapore, South Korea, and Japan, among others, placed nearthe top.

As in the past, though, some education question just what and how much PISA tells us, given social, cultural, and economic differences among nations.

The PISA test is coordinated by the Organization for Economic Cooperation and Development, the OECD.

Andreas Schleicher serves as deputy director for education and skills there. He helped develop and runs the test, and joins us now.

And welcome to you.

ANDREAS SCHLEICHER, Organization for Economic Cooperation and Development: Thank you very much.

JEFFREY BROWN: So, explain to us first, what is the role and importance of these tests? What do they actually tell us?

ANDREAS SCHLEICHER: Well, they allow us to look at what is possible in education.

They show us what the world's leading education systems -- shows possible in terms of student achievement,in terms of equity in educational opportunities, the very important mirror in which we can look at ourselves in the light of what other countries show is possible, really.

JEFFREY BROWN: So when we look at ourselves here in the U.S. the headline once again was average. Is that the -- even as some countries have moved ahead.

ANDREAS SCHLEICHER: Yes.

JEFFREY BROWN: Is that the takeaway that you would put for the U.S.?

ANDREAS SCHLEICHER: Well, yes, I think the U.S. is an average performer.

But we have seen actually a lot of movement around the world, Shanghai, Singapore moving from good to great, in Europe, Poland, Germany actually addressing many of the same challenges the U.S. faces in terms of creating a more equitable distribution of learning opportunities. There a lot of lessons in there, not justsort of seeing where you are, but also how things can become better.

JEFFREY BROWN: Well, one of the criticisms -- you mentioned Shanghai, Singapore. How do you compare them, Shanghai, a city, to the United States, where there are so many huge differences?

ANDREAS SCHLEICHER: Absolutely. That is a very fair point.

It would be more appropriate to compare, for example, Shanghai, the top-performing province in China, withMassachusetts, the top-performing state in the U.S. But, still, you have an average -- a gap of two-and-a-half school years Shanghai leading Massachusetts, so it is relevant for us to look to those places, how they actually deliver those kind of outcomes.

JEFFREY BROWN: So, give us some examples. What do you see some countries doing well that we are not doing here?

ANDREAS SCHLEICHER: Well, A., particularly in East Asia, they give a great value to education. They attract great people into the teaching profession.

They attract the most talented teachers into the most challenging classrooms, something the U.S. has greatdifficulties with. I mean, every student believes that they are the owners of their success, that investment in learning, effort is going to make a difference, not talent.

I think there are a lot of lessons, I think, all over the world can learn from East Asia. But you can alsosee high-performing systems in Europe, or you look to your northern neighbor, Canada, very impressive results in some of the provinces there.

JEFFREY BROWN: And you see them taking actions that have -- you have seen the shift from the last time of the results?

ANDREAS SCHLEICHER: Yes, absolutely.

You know, I mean, Shanghai did really well last time, but they are doing a lot better now. It is not only the relative position that we have seen, but also the pace of change. Also, at the bottom of the list, youcan see a country like Brazil rising from the bottom, Turkey, Mexico. Actually, there is a lot of improvement. Out of 65 countries, 40 have seen some improvement in one of the three subjects.

JEFFREY BROWN: The U.S. has a higher proportion of lower-income students than many of these countries. The U.S. has a more diverse population, including immigrant groups, than many of these countries.

ANDREAS SCHLEICHER: Actually, these are common beliefs. On the income, for example, that is not actuallyright.

In terms of child poverty, the U.S. is around the average. Among the OECD countries, it has a more diversepopulation. But even if you account for all of those factors, you know, to take Vietnam, a country that isactually where every child lives in poverty, and still its results come out better than the OECD average.

So poverty is a challenge, but you can actually see some countries very good at moderating inequalities, very good at helping disadvantaged students actually to excel. You can see that in Asia and Singapore and Japan. You can see that in Northern Europe, where you have children coming out of poverty, but the education system then assures that those children get the best educational opportunities.

JEFFREY BROWN: These numbers are inevitably pounced upon by advocates of all kind, right?

Once we know the results of the tests, can we therefore say policy X is the right way to go, policy Y for any particular country? And I am thinking specifically of the U.S. here. We have these -- have all kinds of discussions and debates on the table.

ANDREAS SCHLEICHER: It is always hard to discern to cause and effect when you have a study like this.

And you can't copy and paste an education system. But I do think what the comparisons allow you, they allow you to study the drivers of success. What have those countries actually done that have moved upwards andhave realized good results?

And then to think about how you can configure those drivers in your own context. Actually, a country that is doing that really well is Singapore. If you go to Singapore, you find nothing that you haven't seen somewhere else, but they made it really work coherently over time, coherently across the whole system. They are very, very good at policy implementation.

JEFFREY BROWN: Well, but you mentioned Singapore again. And people say Singapore. OK, that is an interesting country. It's a smaller country. It has a much more regime -- much stricter regime than -- and it is a different form of government in a way than the U.S.

ANDREAS SCHLEICHER: Let me give you another example.

JEFFREY BROWN: OK.

ANDREAS SCHLEICHER: In the year 2000, my own country, Germany, came out quite poorly on PISA, both in terms of average performance and in terms of the achievement gap.

But the country has really worked hard on those kind of issues, giving immigrant students better chances in school, investing into the teaching of lower-income students. And the performance gap between the richerand the less wealthier children has halved in the period of nine years. So, actually, these are challenges, but, actually, there are very good examples, Poland, another middle-income country that has seen dramatic improvements on its learning outcomes...

(CROSSTALK)

JEFFREY BROWN: So, just in our last 30 seconds, your advice is, use the -- get past the headlines...

ANDREAS SCHLEICHER: Right.

JEFFREY BROWN: ... and try to see what can work in a given country?

ANDREAS SCHLEICHER: Absolutely.

The world is a fantastic laboratory. We can actually see different ideas playing out in different ways, and we can actually -- we don't have to copy every mistake that is being made. But we can look at how have ideas like choice, like competition, like standards, how they have been played out?

And the U.S., I think, has made -- is one great example. If you look at the Common Core standards that arenow being implemented by states, this is exactly an idea like this, internationally benchmarked. They are actually modeled on the top-performing education systems. If they are actually done in classrooms, they are going to get the U.S. pretty much upwards.

JEFFREY BROWN: All right.

Well, that is an ongoing example that we will be watching over time.

Andreas Schleicher of the OECD, thank you very much.

ANDREAS SCHLEICHER: Thank you very much.