According to a new report, the graduation exams required by many states are not worth much, either to the student or the rest of us.

Many high school graduation tests don’t measure whether students are ready for college or work, and some states haven’t even made clear what the purpose of their test is, a study finds. Most of the states gear their tests toward 10th or 11th grade learning, and some gauge pre-9th grade skills, according to a study released Wednesday by the Center on Education Policy, a nonprofit research group.

The fact that these tests are close to worthless as an assessment of student knowledge is bad enough. Worse is that the curriculum and much of the time and effort in many schools is now being focused on getting students to pass the tests. And too many students still fail them. Standardized tests are not the key to improving teaching and learning and the jokes being offered as exit exams in more than half the states are even worse. They’re political smokescreens that impede real efforts to change high school education.