The following editorial appeared in Thursday’s Washington Post.

Educators who are successful in turning around troubled schools say the first step is collecting reliable data. A true measure of performance is the only way to identify problems and map improvement.

Yet five years into the No Child Left Behind Act and its mandate for accountability, too many states still are gaming the system by administering weak tests. They boast about high scores, but their claims are as phony as the performance of their students.

Ending this fraud is among the reforms being pushed by a blue-ribbon commission on No Child Left Behind. The group, led by former Health and Human Services Secretary Tommy G. Thompson, and former Georgia Gov. Roy E. Barnes, points out that setting intentionally low-test standards allows students to post better results and lets states escape sanctions under the law. It also makes comparing the performance of students between states impossible and presents a misleading picture of how well schools and their students are doing. This hypocrisy has become an annual event in which states post the results of achievement tests that in many cases differ widely from the results of benchmark tests given by the National Assessment of Educational Progress.

Though the commission correctly diagnosed the problem, it has fallen short with its call for the federal government to require tougher tests from the states or for states to voluntarily use a national model. It’s time for the United States to move in the direction taken by other countries in formulating and administering a national test. All students, no matter where they live, should have to show proficiency in certain skills and knowledge. The reason no such test exists has more to do with politics than education. Presidents George H.W. Bush and Bill Clinton both tried to get national standards introduced, but their efforts were quashed by conservatives committed to local control of schools and by liberals averse to more testing. Children’s rights trumps states’ rights, and geography shouldn’t matter in how well prepared students are. Shouldn’t third-grade reading in Mississippi be the same as in Maryland? Even more urgent, given the competition the United States faces in a global economy, shouldn’t an eighth-grader from Georgia or Pennsylvania have the same math skills as any counterpart in Singapore or Denmark?

There are other good reasons for introducing a national test, including the economic (money would be saved by using just one test) and the pragmatic (the debate would be how to teach instead of what to test).The arguments for a national test are so strong that some states are looking to form partnerships with others in developing common tests. As Congress begins to debate the reauthorization of No Child Left Behind, it should ask this question: Why wouldn’t the nation want, finally, to know how well all of its students perform?