Learning That Lasts
A Most students know the feeling of studying hard for an exam and then forgetting much of the material within weeks. In the 1880s the German psychologist Hermann Ebbinghaus tested this experience on himself. He memorised lists of meaningless syllables, then measured how many he could recall after different delays. His results showed what is now called the forgetting curve: memory fades quickly at first, and then more slowly.
B Ebbinghaus also found that reviewing material reduced the speed of forgetting, and that reviews spread over several days worked better than the same time spent in one session. Modern researchers call this the spacing effect. Many later experiments, with school pupils as well as university students, have supported it. The effect is strongest when each review takes place just as the material is starting to be forgotten, because recalling it then takes effort, and effort strengthens the memory.
C Despite this evidence, many students still cram, studying in a single long session just before a test. Cramming can produce good marks in a test taken the next morning, which is why the habit persists, but the knowledge disappears rapidly. Teachers could help by planning courses so that important topics return at intervals instead of being taught once and then dropped.
D A related finding concerns testing. Trying to recall information from memory, instead of simply rereading it, has been shown to improve long-term retention. Researchers refer to this as the testing effect. Students often prefer rereading because it feels easier and more familiar, but this feeling of familiarity can be misleading, as it may make them overconfident. Short quizzes, flashcards and practice questions all make use of the testing effect.
E Technology has made it easy to put these ideas to use. Several language-learning applications now schedule reviews automatically, showing a word again after a longer gap each time it is remembered correctly. The writer cautions, however, that no application can replace motivation: a schedule helps only if the learner actually follows it. Used together, spacing and self-testing allow students to learn more in less time, though not without effort.