The idea behind standardized testing is that everyone gets the chance to perform on the same test in the same circumstances. In an ideal world, this should create a system where everyone’s test results are a good indicator of their skills, learning, and hard work.
The reality, of course, is different. Standardized testing faces a host of criticisms, some more valid than others. But even if we assume that everyone walks into a standardized test with the same background, when the test happens matters. The timing of the test itself can have a marked impact on student scores, according to a new paper in PNAS.
The paper found that the later in the day a standardized test was held, the lower the scores were. That’s an important finding, given how much rests on standardized test results. These tests not only form the basis of education policy in countries all over the world, but they're often also used to decide how funding should be distributed among schools. And, most obvious of all, a test score can determine the course of a student’s life.