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To Learn, Retrieve

Mike Ebersold is a neurosurgeon. In neurosurgery and indeed life there is an essential kind of learning that only comes from reflection on personal experience.

In the book Make It Stick: The Science of Successful Learning, the authors capture Ebersold’s description:

A lot of times something would come up in surgery that I had difficulty with, and then I’d go home that night thinking about what happened and what could I do, for example, to improve the way a suturing went. How can I take a bigger bite with my needle, or a smaller bite, or should the stitches be closer together? What if I modified it this way or that way? Then the next day back, I’d try that and see if it worked better. Or even if it wasn’t the next day, at least I’ve thought through this, and in so doing I’ve not only revisited things that I learned from lectures or from watching others performing surgery but also I’ve complemented that by adding something of my own to it that I missed during the teaching process.

“Reflection,” Ebersold says, “can involve several cognitive activities that lead to stronger learning: retrieving knowledge and earlier training from memory, connecting these to new experiences, and visualizing and mentally rehearsing what you might do differently next time.”

The authors of Make It Stick continue:

To make sure the new learning is available when it’s needed, Ebersold points out, “you memorize the list of things that you need to worry about in a given situation: steps A, B, C, and D,” and you drill on them. Then there comes a time when you get into a tight situation and it’s no longer a matter of thinking through the steps, it’s a matter of reflexively taking the correct action.

“Unless you keep recalling this maneuver,” Ebersold notes, “it will not become a reflex. Like a race car driver in a tight situation or a quarterback dodging a tackle, you’ve got to act out of reflex before you’ve even had time to think. Recalling it over and over, practicing it over and over. That’s just so important.”

The Testing Effect

The power of retrieval as a learning tool is known among psychologists as the testing effect. In its most common form, testing is used to measure learning and assign grades in school, but we’ve long known that the act of retrieving knowledge from memory has the effect of making that knowledge easier to call up again in the future.

Aristotle Exercise

Francis Bacon and William James also wrote about this phenomenon. Retrieval makes things stick better than re-exposure to the original material. This is the testing effect.

To be most effective, retrieval must be repeated again and again, in spaced out sessions so that the recall, rather than becoming a mindless recitation, requires some cognitive effort. Repeated recall appears to help memory consolidate into a cohesive representation in the brain and to strengthen and multiply the neural routes by which the knowledge can later be retrieved. In recent decades, studies have confirmed what Mike Ebersold and every seasoned quarterback, jet pilot, and teenaged texter knows from experience—that repeated retrieval can so embed knowledge and skills that they become reflexive: the brain acts before the mind has time to think.

Learning or Just Recalling Information?

In 2010 the New York Times reported on a scientific study that showed that students who read a passage of text and then took a test asking them to recall what they had read retained an astonishing 50 percent more of the information a week later than students who had not been tested.

This would seem like good news, but here’s how it was greeted in many online comments:

  • “Once again, another author confuses learning with recalling information.”
  • “I personally would like to avoid as many tests as possible, especially with my grade on the line. Trying to learn in a stressful environment is no way to help retain information.”
  • “Nobody should care whether memorization is enhanced by practice testing or not. Our children cannot do much of anything anymore.”

Forget memorization, many commenters argued; education should be about high-order skills. Hmmm. If memorization is irrelevant to complex problem solving, don’t tell your neurosurgeon. The frustration many people feel toward standardized, “dipstick” tests given for the sole purpose of measuring learning is understandable, but it steers us away from appreciating one of the most potent learning tools available to us. Pitting the learning of basic knowledge against the development of creative thinking is a false choice. Both need to be cultivated. The stronger one’s knowledge about the subject at hand, the more nuanced one’s creativity can be in addressing a new problem. Just as knowledge amounts to little without the exercise of ingenuity and imagination, creativity absent a sturdy foundation of knowledge builds a shaky house.

The Takeaway

Practice at retrieving new knowledge or skill from memory is a potent tool for learning and durable retention. This is true for anything the brain is asked to remember and call up again in the future—facts, complex concepts, problem-solving techniques, motor skills.

Effortful retrieval makes for stronger learning and retention. We’re easily seduced into believing that learning is better when it’s easier, but the research shows the opposite: when the mind has to work, learning sticks better. The greater the effort to retrieve learning, provided that you succeed, the more that learning is strengthened by retrieval. After an initial test, delaying subsequent retrieval practice is more potent for reinforcing retention than immediate practice, because delayed retrieval requires more effort.

Repeated retrieval not only makes memories more durable but produces knowledge that can be retrieved more readily, in more varied settings, and applied to a wider variety of problems.

While cramming can produce better scores on an immediate exam, the advantage quickly fades because there is much greater forgetting after rereading than after retrieval practice. The benefits of retrieval practice are long-term.

Simply including one test (retrieval practice) in a class yields a large improvement in final exam scores, and gains continue to increase as the frequency of classroom testing increases.

Testing doesn’t need to be initiated by the instructor. Students can practice retrieval anywhere; no quizzes in the classroom are necessary. Think flashcards—the way second graders learn the multiplication tables can work just as well for learners at any age to quiz themselves on anatomy, mathematics, or law. Self-testing may be unappealing because it takes more effort than rereading, but as noted already, the greater the effort at retrieval, the more will be retained.

Students who take practice tests have a better grasp of their progress than those who simply reread the material. Similarly, such testing enables an instructor to spot gaps and misconceptions and adapt instruction to correct them.

Giving students corrective feedback after tests keeps them from incorrectly retaining material they have misunderstood and produces better learning of the correct answers.

Students in classes that incorporate low-stakes quizzing come to embrace the practice. Students who are tested frequently rate their classes more favorably.

Make It Stick: The Science of Successful Learning is worth reading in its entirety.