Like most students, you’ve probably crammed the night before an exam. And after it, you probably did OK or maybe you even did well, but did you remember any of what you learned after the exam? One evidence-based way to better remember what you’ve learned is through Spaced Repetition, or spacing out your learning and practice of new knowledge or skills. Although this might seem novel, this is hardly a new concept; it was first described in 1885 by a German psychologist named Herman Ebbinghaus. Here’s how it works. Say you plot your retention, or how much you remember of something, vs. time. Now you learn that something on day 0. Without reviewing it, the “forgetting curve” will look like an exponentially decaying curve, which is kind of scary! If you review the material at increasingly spaced intervals after learning it, then the forgetting curve starts to flatten out and you’ll get a lot better longer-term retention. Now, the goal here is to review the material at the right time. It turns out that the best time to revisit information that you are trying to learn is right around the time you would naturally forget it. Since forgetting typically follows this exponential curve, the trick becomes timing your study sessions around it. Practically, this means having more widely spaced intervals between study times for the material that you are more familiar with, and shorter intervals between study sessions for material that you are less familiar with. While this strategy would be effective for all fields of study, it is especially important for students in the medical field, who have to retain key knowledge and skills in order to care for their patients. Kind of frighteningly, one study found that without spaced repetition, after one year medical students forgot up to 33% of their basic science knowledge, and after two years, more than 50%! But when students and residents applied spaced repetition strategies in their studying, they significantly outperform their counterparts, with some studies showing close to 40% greater learning efficiency.

Knowing about spaced-repetition is one thing, but what about applying it? Students—especially those in the health and medical fields—have to remember hundreds or even thousands of “bits” of knowledge and skills. Because of this, it would be incredibly hard for them to keep track of when they should revisit each piece of information—especially since each bit of information will follow its own learning curve. This is why researchers and software developers are using computer algorithms to try to help students optimize their studying. These algorithms help you learn by sorting information based on your responses to questions—so if you get a question wrong, they will automatically prioritize that information for repetition over the information in questions you answered correctly. In doing this, these algorithms can actually reduce your overall study time by making sure the time you are spending studying for your exams isn’t wasted on studying information that you can already reliably recall. One of the best parts of spaced repetition is that it suggests that we can gain a lot by studying smarter, not necessarily longer. With just a little more organization or forethought on your part, you can achieve a whole lot more. That said, spaced repetition means challenging yourself to apply your learning right at the point where you’re starting to forget it, and that can sometimes be kind of hard! So, just know that if a spaced repetition regimen feels difficult, even frustrating, that can mean that it’s doing exactly what it’s supposed to be doing. Okay one final point. In some fields certain knowledge may change relatively quickly because of new discoveries, so it’s important to know the right new information, rather than remembering the wrong old information for a long time. That’s why you should make sure that the tools you use to do the spacing are also designed to help you stay current. Alright time to get studying.