Make It Stick: The Science of Successful Learning

by Peter C. Brown

we also apply two of the primary learning principles in the book: spaced repetition of key ideas, and the interleaving of different but related topics.

Cognitive psychology is the basic science of understanding how the mind works, conducting empirical research into how people perceive, remember, and think.

Much research turns this belief on its head: when learning is harder, it’s stronger and lasts longer.

Learning is stronger when it matters, when the abstract is made concrete and personal.

repetition by itself does not lead to good long-term memory.

It makes sense to reread a text once if there’s been a meaningful lapse of time since the first reading, but doing multiple readings in close succession is a time-consuming study strategy that yields negligible benefits at the expense of much more effective strategies that take less time.

rising familiarity with a text and fluency in reading it can create an illusion of mastery.

Mastery in any field, from cooking to chess to brain surgery, is a gradual accretion of knowledge, conceptual understanding, judgment, and skill. These are the fruits of variety in the practice of new skills, and of striving, reflection, and mental rehearsal.

But if we stop thinking of testing as a dipstick to measure learning—if we think of it as practicing retrieval of learning from memory rather than “testing,” we open ourselves to another possibility: the use of testing as a tool for learning.

One of the best habits a learner can instill in herself is regular self-quizzing to recalibrate her understanding of what she does and does not know.

The good news is that we now know of simple and practical strategies that anybody can use, at any point in life, to learn better and remember longer: various forms of retrieval practice, such as low-stakes quizzing and self-testing, spacing out practice, interleaving the practice of different but related topics or skills, trying to solve a problem before being taught the solution, distilling the underlying principles or rules that differentiate types of problems, and so on.

Reflection 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.

In very short order we lose something like 70 percent of what we’ve just heard or read. After that, forgetting begins to slow, and the last 30 percent or so falls away more slowly,

Today, we know from empirical research that practicing retrieval makes learning stick far better than reexposure to the original material does.

retrieval-practice 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.

One argument suggested that the greater effort required by the delayed recall solidified the memory better.

When retrieval practice is spaced, allowing some forgetting to occur between tests, it leads to stronger long-term retention than when it is massed.

How does giving feedback on wrong answers to test questions affect learning? Studies show that giving feedback strengthens retention more than testing alone does, and, interestingly, some evidence shows that delaying the feedback briefly produces better long-term learning than immediate feedback.

Delayed feedback on written tests may help because it gives the student practice that’s spaced out in time; as discussed in the next chapter, spacing practice improves retention.13

Tests that require the learner to supply the answer, like an essay or short-answer test, or simply practice with flashcards, appear to be more effective than simple recognition tests like multiple choice or true/false tests.

where more cognitive effort is required for retrieval, greater retention results.

Practice at retrieving new knowledge or skill from memory is a potent tool for learning and durable retention.

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.

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.

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

Why is spaced practice more effective than massed practice? It appears that embedding new learning in long-term memory requires a process of consolidation, in which memory traces (the brain’s representations of the new learning) are strengthened, given meaning, and connected to prior knowledge—a process that unfolds over hours and may take several days. Rapid-fire practice leans on short-term memory. Durable learning, however, requires time for mental rehearsal and the other processes of consolidation. Hence, spaced practice works better.

the research shows unequivocally that mastery and long-term retention are much better if you interleave practice than if you mass it.

The basic idea is that varied practice—like tossing your beanbags into baskets at mixed distances—improves your ability to transfer learning from one situation and apply it successfully to another.

You develop a broader understanding of the relationships between different conditions and the movements required to succeed in them; you discern context better and develop a more flexible “movement vocabulary”—different movements for different situations.

One form of practice that helps us learn from experience, as the neurosurgeon Mike Ebersold recounted in Chapter 2, is reflection. Some people are more given to the act of reflection than others, so Doug Larsen has broadened his research to study how you might structure reflection as an integral part of the

scientists call this heightened performance during the acquisition phase of a skill “momentary strength” and distinguish it from “underlying habit strength.” The very techniques that build habit strength, like spacing, interleaving, and variation, slow visible acquisition and fail to deliver the improvement during practice that helps to motivate and reinforce our efforts.12 Cramming, a form of massed practice, has been likened to binge-and-purge eating.

The simple act of spacing out study and practice in installments and allowing time to elapse between them makes both the learning and the memory stronger, in effect building habit strength. How big an interval, you ask? The simple answer: enough so that practice doesn’t become a mindless repetition. At a minimum, enough time so that a little forgetting has set in.

Something as simple as a deck of flashcards can provide an example of spacing.

the better your mastery, the less frequent the practice, but if it’s important to retain, it will never disappear completely from your set of practice boxes.

Beware of the familiarity trap: the feeling that you know something and no longer need to practice it.

Interleaving two or more subjects during practice also provides a form of spacing. Interleaving can also help you develop your ability to discriminate later between different kinds of problems and select the right tool from your growing toolkit of solutions.

Like interleaving, varied practice helps learners build a broad schema, an ability to assess changing conditions and adjust responses to fit. Arguably, interleaving and variation help learners reach beyond memorization to higher levels of conceptual learning and application, building more rounded, deep, and durable learning, what in motor skills shows up as underlying habit strength.

Spacing, interleaving, and variability are natural features of how we conduct our lives.

Short-term impediments that make for stronger learning have come to be called desirable difficulties,

This process of converting sensory perceptions into meaningful representations in the brain is still not perfectly understood. We call the process encoding, and we call the new representations within the brain memory traces. Think of notes jotted or sketched on a scratchpad, our short-term memory.

The process of strengthening these mental representations for long-term memory is called consolidation.

In consolidation, the brain reorganizes and stabilizes the memory traces. This may occur over several hours or longer and involves deep processing of the new material, during which scientists believe that the brain replays or rehearses the learning, giving it meaning, filling in blank spots, and making connections to past experiences and to other knowledge already stored in long-term memory. Prior knowledge is a prerequisite for making sense of new learning, and forming those connections is an important task of consolidation.

An apt analogy for how the brain consolidates new learning may be the experience of composing an essay. The first draft is rangy, imprecise. You discover what you want to say by trying to write it. After a couple of revisions you have sharpened the piece and cut away some of the extraneous points. You put it aside to let it ferment. When you pick it up again a day or two later, what you want to say has become clearer in your mind.

Knowledge, skills, and experiences that are vivid and hold significance, and those that are periodically practiced, stay with us.

There’s virtually no limit to how much learning we can remember as long as we relate it to what we already know.

In fact, because new learning depends on prior learning, the more we learn, the more possible connections we create for further learning.

Our retrieval capacity, though, is sev...

How readily you can recall knowledge from your internal archives is determined by context, by recent use, and by the number and vividness of cues that you have linked to the knowledge and can call on to help bring it forth.