The United States lags behind most other developed countries when it comes to science education.

That, at least, is one conclusion of a major report released Tuesday by the Organisation for Economic Cooperation and Development (OECD). It measures student literacy in science, math, and reading (focusing this year on science) among 15-year-olds, and is an often-cited reference for policymakers sounding the alarm bells about the state of education in the United States and its implications for the ability of Americans to secure jobs in a global economy.

Finland emerged at the top of 57 countries in science, according to the 2006 survey results from the Programme for International Student Assessment (PISA). The US ranked 29th, behind countries like Croatia, the Czech Republic, and Liechtenstein, and ahead of just nine other OECD countries.

"What once was the gold standard [for international education] is now not even at the OECD average, which shows you how much the world has changed," says Andreas Schleicher, who helped write the report. The US is average in the number of students at the highest levels of scientific literacy, but has a much larger pool – nearly 1 in 4 – at the bottom, Mr. Schleicher notes. "We have stand-alone studies that suggest these kids have grim prospects in the labor market," he says.

That worry has energized education advocates and reformers, who see the test as a useful tool to catalyze public opinion behind the need for fundamental change in how America educates.

"To most policymakers there's almost a believed connection between how well our kids do in school and how well our economy does in the global economy," says Marc Tucker, president of the National Center on Education and the Economy. "To the extent that you have first-class bulletproof studies saying this over and over, it provides some powerful ammunition... to make the kind of investments in our schools that we really have to make."

Not everyone sees PISA as bulletproof. Comparing something as different as educational systems in countries with different cultures and populations is fraught with complexities; some experts say the rankings are not as straightforward as they might seem.

"People love to cite bad stories," says Clifford Adelman, an associate with the Institute for Higher Education Policy, noting that after each PISA release, experts tend to bemoan America's poor showing. The truth, he says, is more complicated. The US, for instance, typically has a large proportion of students taking the test in a language other than their native one. Some countries track lower performing students into vocational schools where they will not be tested. Other countries are just smaller and more homogenous.

"The question is how you account for that statistically," says Mr. Adelman. In these tests, "I'm comparing [the US] a country of 300-odd million people, a nation of immigrants, that is incredibly diverse with, in the example of Finland, a country of [just under] 6 million people."

Others dismiss such concerns as excuses. "At the end of the day, that young person is going to have to go compete head to head for a job with someone in another country," says Bob Wise, president of the Alliance for Excellent Education and former governor of West Virginia. Rather than focus on America's relatively low standing, he and others would like to see policymakers learn from other countries that have managed to improve their PISA scores, despite large immigrant populations and socioeconomic challenges.

"The lesson from PISA is that it's not enough to test; you have to have the support and strategy to take advantage of what you learn from those tests," says Mr. Wise. "Every community is not wired to the world, and every child needs to have an education that looks good not compared to the county next door, but internationally."