Despite their reputation as a cruel tool of teachers intent on striking fear into the hearts of unprepared students, quizzes — given early and often — may be a student’s best friend when it comes to understanding and retaining information for the long haul, suggests new psychology research from WUSTL.
“Our study indicates that testing can be used as a powerful means for improving learning, not just assessing it,” said Henry L. “Roddy” Roediger III, Ph.D., the James S. McDonnell Distinguished University Professor and an internationally recognized scholar of human memory function. “Students who self-test frequently while studying on their own may be able to learn more, in much less time, than they might by simply studying the material over and over again.
“Incorporating more frequent classroom testing into a course may improve students’ learning and promote retention of material long after a course has ended.”
Perhaps equally important, this study demonstrates that students who rely on repeated study alone often come away with a false sense of confidence about their mastery of the material.
In an experiment in which students either took quizzes or were permitted to study material repeatedly, students in the study-only group professed an exaggerated confidence, sure that they knew the material well, even though important details already had begun slip-sliding away. The group that took tests on the material, rather than repeatedly reading it, actually did better on a delayed test of their knowledge.
Recently published in the journal Psychological Science, Roediger’s study was co-authored with graduate student Jeffrey D. Karpicke, a research colleague in the Department of Psychology in Arts & Sciences.
In two experiments, one group of students studied a prose passage for about five minutes and then took either one or three immediate free-recall tests, receiving no feedback on the accuracy of answers. Another group received no tests in this phase, but was allowed another five minutes to restudy the passage each time their counterparts were involved in a testing session.
After phase one, each student was asked to take a final retention test presented at one of three intervals — five minutes, two days or one week later. When the final test was presented five minutes after the last study or testing session, the study-study-study-study (SSSS) group initially scored better, recalling 81 percent of the passage as opposed to 75 percent for the repeated-test group.
However, tested just two days later, the study-only group had forgotten much of what they had learned, already scoring slightly lower than the repeated-test group. Tested one week later, the study-test-test-test group scored dramatically better, remembering 61 percent of the passage as compared with only 40 percent by the study-only group.
The study-only group had read the passage about 14 times, but still recalled less than the repeated testing group, which had read the passage only 3.4 times in its one and only study session.
“Taking a memory test not only assesses what one knows, but also enhances later retention, a phenomenon known as the ‘testing effect,'” Roediger said.
“Our findings demonstrate that the testing effect is not simply a result of students gaining re-exposure to the material during testing, because students in our repeated-study group had multiple opportunities to re-experience 100 percent of the material but still produced poor long-term retention.
“Clearly, testing enhances long-term retention through some mechanism that is both different from and more effective than restudy alone.”
Previous research, Roediger said, offers a number of theories on why this phenomenon takes place. One suggests we learn more efficiently when placed in difficult situations — think of that sinking feeling in your stomach when a pop quiz is announced.
Others suggest that repeated testing improves long-term recall by forcing students to practice the very skills they will need to recollect this information at a later date, a memory quirk that might be called the “use-it or lose-it” effect.
The fact that study-only students did relatively well when tested after only five minutes is consistent with other research showing that massed presentation or “cramming” improves performance primarily in the short-run, whereas studies spaced over intervals tend to result in better long-term retention.
This study, Roediger said, reveals just how strong the testing effect is: Even though repeated study across intervals offers known benefits to long-term retention, students in the repeated-testing group still produced much better results on a delayed test of recollection.
Roediger is involved in number of research projects designed to use new knowledge from the cognitive sciences to improve classroom instruction. This research was supported by a grant from the Institute of Educational Sciences and by a Collaborative Activity Grant from the James S. McDonnell Foundation.
Although the participants in this study were college undergraduates ages 18-24, the study’s findings have important implications for all classrooms. Many students, Roediger noted, continue to rely heavily on repeated-study techniques, often with the encouragement of their teachers.
Even better long-term retention may be possible, he suggests, if students are alerted that they will be tested often, encouraged to review at least once before each test and then given timely feedback on the accuracy of their answers.
“We believe the time is ripe for a thorough examination of the mnemonic benefits of testing and its potentially important consequences for improving childhood educational practice,” he said.