American public schools increasingly rely on standardized testing to measure student achievement and teacher quality. When students perform poorly on a test, their teachers or schools are generally seen as ineffective—and can suffer consequences.
But research suggests there could be a simple way to raise standardized test scores: when possible, schedule more time between tests or testing sessions.
University of Chicago PhD candidate Ian Fillmore and Chicago Booth’s Devin G. Pope studied Advanced Placement tests taken each spring by tens of thousands of US and Canadian high-school students. Students take the tests to earn college credit for classes taken in high school. The test dates, which are set by the College Board and vary by subject, change every year.
The researchers analyzed a 10 percent sample of all AP exam-takers between 1996 and 2001 who took two AP exams the same year. It included thousands of students who were tested on the same two AP subjects but with varied time gaps between their two exams.
The findings indicate that leaving more days between tests can make a significant difference on outcomes. Students who took exams with 10 days of separation were 8 percent more likely to pass both exams than students who took the same two exams with only one day of separation.
The data demonstrate that cognitive fatigue occurs when mental tasks are scheduled close together, similar to how physical fatigue occurs when physical activities are done in close succession. Performance improved in a linear manner with more time, indicating that each extra day added a boost equal to the one before it. The researchers find that increasing the time between the two exams from one to 10 days improved scores by approximately 0.15 points (the College Board scores each test on a scale of 1 to 5, which means students taking two exams could earn a total of 10 points). The additional points were significant enough to steadily improve the student's chances of passing both exams.