Students of all ages might improve their test scores if the category of information changed abruptly midway through the test, according to a new study. “The simple act of testing harms memory,” says Amy Criss, assistant professor of psychology at Syracuse University. “Previous studies have shown that people are more accurate in their responses to questions at the beginning of a test than they are at the end of a test. “This is called output interference. Our study demonstrates how to minimize the effects of output interference.” As reported in the journal Psychological Science, Criss and colleagues from the University of South Florida and Indiana University looked at how output interference can be minimized when people are trying to recall information or answer a series of questions over a relatively long period of time, such as in standardized testing. The researchers found that simply changing the subject matter of the questions increases accuracy on longer tests. In the study, test subjects were asked to memorize word sets from different categories, such as animal and geographic terms, or countries and professions. The testers were then split into three groups, each of which responded to a series of 150 questions. The tests included 75 terms from each word set. The first group of testers responded to questions in which the terms were randomly intermixed. A second group responded to 75 questions about one category followed by 75 questions from the second category. The third group responded to alternating blocks of five questions about each category. The second group out performed its counterparts on the test. “While accuracy fell off as the test subjects neared the end of the first category of terms, the accuracy rebounded when the questions switched to the second category of terms,” Criss says. “The study demonstrates that memory improves when categories of information people are asked to remember change.” The results have implications for the way in which standardized and comprehensive tests are created, Criss says. “You don’t want to place a lot of the same information into one section of the test. Accuracy will increase by changing the subject matter of the questions.” The results also have implications for student study habits. “While it’s natural for students to complete one subject before moving on to the next, if you look at the data, students may have better results if they work on one subject for a little while, move to something completely different and then go back to the first subject,” Criss says. The National Science Foundation (NSF) and the Air Force Office of Scientific Research funded the study.