Learning from Mistakes

In the latest Mind Matters, the psychologists Henry L. Roediger and Bridgid Finn review some interesting new work by Nate Kornell and colleagues, which looked at the advantages of learning through error. Conventional pedagogy assumes that the best way to teach children is to have them repeatedly practice once they know the right answer, so that the correct response gets embedded into the brain. (According to this approach, it's important to avoid mistakes while learning so that our mistakes get accidentally reinforced.) But this error-free process turns out to be inefficient: Kids learn material much faster when they screw-up first. In other words, getting the wrong answer helps us remember the right one.

Students were asked to read the essay [on vision] and prepare for a test on it. However, in the pretest condition they were asked questions about the passage before reading it such as "What is total color blindness caused by brain damage called?" Asking these kinds of question before reading the passage obviously focuses students' attention on the critical concepts. To control this "direction of attention" issue, in the control condition students were either given additional time to study, or the researchers focused their attention on the critical passages in one of several ways: by italicizing the critical section, by bolding the key term that would be tested, or by a combination of strategies. However, in all the experiments they found an advantage in having students first guess the answers. The effect was about the same magnitude, around 10 percent, as in the previous set of experiments.

The scientists go on to offer some practical advice:

By challenging ourselves to retrieve or generate answers we can improve our recall. Keep that in mind next time you turn to Google for an answer, and give yourself a little more time to come up with the answer on your own.

Students might consider taking the questions in the back of the textbook chapter and try to answer them before reading the chapter. (If there are no questions, convert the section headings to questions. If the heading is Pavlovian Conditioning, ask yourself What is Pavlovian conditioning?). Then read the chapter and answer the questions while reading it. When the chapter is finished, go back to the questions and try answering them again. For any you miss, restudy that section of the chapter. Then wait a few days and try to answer the questions again (restudying when you need to). Keep this practice up on all the chapters you read before the exam and you will be have learned the material in a durable manner and be able to retrieve it long after you have left the course.

This work builds on a large body of research demonstrating the importance of making mistakes and "active learning". (I love the Niels Bohr quote: "An expert is a person who has made all the mistakes that can be made in a very narrow field.") In How We Decide, and in a recent article on grit, I wrote about the influential research of Carol Dweck, who has documented the importance of encouraging children to challenge themselves, even if it means getting things wrong.

In a recent paper, Dweck and colleagues demonstrated that teaching at-risk seventh-graders about the growth mindset - this included lessons about the importance of effort - led to significantly improved grades for the rest of middle school.

Interestingly, it also appears that praising children for their intelligence can make them less likely to persist in the face of challenges, a crucial element of grit. For much of the last decade, Dweck and her colleagues have tracked hundreds of fifth-graders in 12 different New York City schools. The children were randomly assigned to two groups, both of which took an age-appropriate version of the IQ test. After taking the test, one group was praised for their intelligence - "You must be smart at this," the researcher said - while the other group was praised for their effort and told they "must have worked really hard."

Dweck then gave the same fifth-graders another test. This test was designed to be extremely difficult - it was an intelligence test for eighth-graders - but Dweck wanted to see how they would respond to the challenge. The students who were initially praised for their effort worked hard at figuring out the puzzles, even though they made lots of mistakes and got low scores. Kids praised for their smarts, on the other hand, quickly became discouraged; they saw their mistakes as a sign of failure.

The final round of intelligence tests was the same difficulty level as the initial test. The students who had been praised for their effort raised their score, on average, by 30 percent. This result was even more impressive when compared to the students who had been praised for their intelligence: their scores on the final test dropped by nearly 20 percent. A big part of success, Dweck says, stems from our beliefs about what leads to success.