Standardized tests. The name says it all: If your scores are lower than your peers, you’re probably below par. But many factors go into a test score, from scholastic aptitude and knowledge to growing up in poverty or affluence. Now, you can add one more item to that list: what time the test is taken. Researchers analyzed the test results of 2 million Danish school children between the ages of 8 and 15 to see whether the time of day they took their nation's comprehensive national test had any effect on performance. Because the test-taking schedule was determined by the availability of computers and class schedule, the timing was essentially random for the students. And the effect was clear. amounting to a nearly 1% drop in scores per hour, the team reports today in the Proceedings of the National Academy of Sciences. But there's some good news. Students tested after a half-hour recess got a 1.7% bump. So if you have to test them in the afternoon, at least give the kids a break.