Turning a medical student into a doctor takes a whole lot of knowledge. B. Price Kerfoot, an associate professor of surgery at Harvard Medical School, was frustrated at how much knowledge his students seemed to forget over the course of their education. He suspected this was because they engaged in what he calls “binge and purge” learning: They stuffed themselves full of facts and then spewed them out at test time. Research in cognitive science shows that this is a very poor way to retain information, as Kerfoot discovered when he went looking in the academic literature for answers. But he also stumbled upon a method that really is effective, called spaced repetition. Kerfoot devised a simple digital tool to make engaging in spaced repetition almost effortless. In more than two dozen studies published over the past five years, he has demonstrated that spaced repetition works, increasing knowledge retention by up to 50 percent. And Kerfoot’s method is easily adapted by anyone who needs to learn and remember, not just those pursuing MDs.
The theory behind spaced repetition is simple: when we first learn a fact, our memory of it is volatile, subject to change or disappear. Each time we encounter that fact again, however, the memory becomes stronger and more stable—especially if the encounters are spread out over time. Cramming the night before an exam (or a speech or a presentation) is a sure way to make the information vanish from your head a short while later. But exposing yourself to that same information multiple times over weeks or months fixes it firmly in your brain. Kerfoot’s innovation was to make these spaced-out learning sessions easy and convenient. Starting with the knowledge medical students had to master in his own specialty of urology, Kerfoot devised questions about the curriculum, with multiple-choice answers, that he sent in weekly emails to the students participating in the study. The students took a few minutes to answer the questions on their laptops or smartphones; each week brought a new round of queries, mixing new material with material already covered. At the end of the year, the students who received the spaced emails scored significantly higher on a test of their urology knowledge.
Since that first study, published in the journal Medical Education in 2007, Kerfoot has evaluated the effectiveness of spacing out exposure to a variety of other topics that doctors in training need to learn, such as performing a physical exam, diagnosing medical ailments, and administering a cancer screening test. In each case, the spaced-out information delivered to students on their devices helped them to recall the information better.
How can you learn like one of Kerfoot’s Harvard Medical School residents? Most email programs allow you to schedule the sending of messages, making it easy to create a spaced-repetition course for yourself. Divide up what you need to know—the text of a speech, the material on an exam—into smaller units, no more than a few sentences long. Then put the information into emails scheduled to be sent to yourself at weekly intervals. To achieve the greatest memory-strengthening effect, mix up old and new material, and put the information in the form of a question to which you’ll have to recall the answer. You’ll find that your email is making you smarter—no all-nighters necessary.
This post originally appeared on Time.com.