Alexandra Starr in slate.com:

You could conclude from these exams that American high-schoolers are ill-taught and ill-prepared for the competitive global economy. But what if you look at these tests like a capitalist rather than an educator? Nothing is at stake for kids when they take the international exams and the NAEP. Students don't even learn how they scored. And that probably affects their performance. American teenagers, in other words, may not be stupid. It could be that when they have nothing to gain (or lose), they're lazy. ...

The dubiousness of these test results becomes clear when you compare them to the results of tests that actually do matter for teenagers: high-school exit exams and college boards. Nineteen states now require their students to pass assessments before they can don a cap and gown; seven others are testing students but not yet withholding diplomas. When states begin imposing penalties for failure, it makes a difference—sometimes a big one. Look at Texas: In 2004, results counted toward graduation for the first time, and pass rates on both the math and English portions of the test leapt almost 20 points.

Starr also reports that scores on the SAT and ACT--tests that have consequences--have increased over the last decade.

Hat tip: Wilson Mixon