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How Spaced Retrieval Works

Written by Katie Converse | Mar 5, 2024 7:08:08 PM

Think back to the last time you met someone new. Can you picture their face? Do you remember their name? Sometimes it can be disconcerting when you forget something simple like a name. If you can’t remember somebody’s name, how will you ever remember everything you need to know on your board exam?

The good news is that forgetting might be essential to long-term learning.

Why forgetting—then remembering—is essential

In 1885 Hermann Ebbinghaus developed the “forgetting curve,” famously illustrating how quickly memory of newly learned material drops off unless it is reinforced by review. Ebbinghaus tested two study methods: Massed practice and spaced repetition. 

  • Massed practice is the repeated study of a topic immediately after learning it.
  • Spaced repetition is the study of a topic at progressively longer intervals—days, weeks, and months after initially learning it.

In the test, spaced repetition (or spaced retrieval) exponentially outperformed massed practice, flattening out the forgetting curve with each review. Numerous studies since then have demonstrated that spaced repetition is most effective when study is timed at the point of forgetting.

Why is forgetting important to learning? 

Some learning researchers theorize that the effort involved in retrieving information from memory is key. Spacing out review in longer and longer intervals forces the mind to reach for the memory, strengthening the “memory muscles.” According to learning researcher Robert Bjork, “the more difficult and involved the retrieval, the more beneficial it is.”

Spaced retrieval also creates varied context—stimuli from various places and times—which serve as memory cues. It helps keep the information fresh, focusing our attention—something that boring old massed practice can’t do.

How to use spaced retrieval

Spaced retrieval is most effective in the form of self-testing—it's the only reliable way to shuttle all this medical knowledge into long-term memory.

Spaced retrieval practice—using flashcards, writing about a topic from memory, or quizzing yourself—has been shown to improve performance over rereading by up to 50%. Memory improves even more when the study time between your spaced reviews is focused on another topic—or interleaving. Both these activities strengthen memory.

So your schedule would look something like this:

  • Day 1: Study a topic
  • Days 2, 4, and 10: Practice recall of that same topic
  • 4 weeks after Day 1: Practice recall of that topic again
  • 4 months after Day 1: Practice recall of that topic one last time

Implementing spaced retrieval and interleaving into your study process may feel like a lot more effort, but if you're simply cramming and forgetting—you'll never get off the proverbial hamster wheel of studying, forgetting, repeating. Stick with it, and all the effort you're putting in will be worth it.

Rather than hoping your brain recognizes the inherent value of the topics on your exam blueprint or the latest guideline update, we recommend you train your brain to remember the material using effortful, effective techniques like spaced repetition.