How do you know you really know something? That’s part of what cognitive scientist Daniel Willingham explains in his new book, “How to Outsmart Your Brain: Why Learning Is Hard and How You Can Make It Easy,” and the focus of the excerpt below.
Willingham has written some pieces for this blog over the course of at least a dozen years, including “A telling experiment reveals a big problem among college students: They don’t know how to study" and “Should kids get time to read for pleasure in school?” and “Most teachers believe that kids have different ‘learning styles.’ Here’s why they are wrong.”
He is the author of several smart and entertaining books, including “Why Don’t Students Like School?” and “When Can You Trust the Experts?” He can be reached at firstname.lastname@example.org, and you can follow him on Twitter @DTWillingham.
Here’s the excerpt from “How to Outsmart Your Brain”:
How to Judge Whether You’re Ready for an ExamA lawyer preparing for the bar exam doesn’t set a time — say, one hundred hours — that she’ll study, and then stick to that plan. She evaluates her learning as she goes, and stops when she thinks she’s mastered the material. Thus, learners must be confident that their judgments about what they know are accurate.Yet you’ve surely had the experience of thinking you were ready for a test and then somehow doing poorly anyway. People in this situation often blame the test. They figure “I know I knew the content. Therefore, there must be something wrong with the test because it did not show that I knew it.” But your judgment “I knew the content” is the result of a mental assessment. Maybe that was the lousy test, not the exam the instructor administered. It’s surprising, but people can be mistaken about what they know.Many factors contribute to judgments of learningSuppose you are taking a conservation biology course, and you want this fact in memory: the red-handed howler monkey is native to Brazil. How would you know whether you’ve learned it? Easy: ask yourself “the red-handed howler monkey is native to which country?” and see what pops out of your memory. Certainly, that’s one way to judge whether you know something, and it’s a good one.But people confuse performance and learning. Here’s the difference. Suppose I see you right after a workout, and you tell me you’ve been practicing push-ups, and can do twenty. I say “cool, show me!” You might say “I can’t now; I’m tired from my workout.” You’ve learned to do twenty push-ups, but your performance wouldn’t show that learning in the current circumstances.When it comes to learning, “performance” means saying “Brazil” in response to the question “the red handed howler is native to which country?” You can see why you would think to yourself “I answered the question so I definitely know that one.” But the fact that you can answer it now (under one set of conditions) doesn’t mean that you could reliably access that memory under all circumstances.For example, you might have learned to speak conversational Japanese pretty well, but your performance with a Japanese border agent doesn’t show your learning because you are tired from your flight and a little nervous. (Or maybe it’s just me who gets nervous for no reason when talking to border agents.)Typically people overestimate what they know because they test their knowledge in ways that, without their realizing it, supports their performance. Thus, they judge they have learned something because their performance is good, but their memory is actually shaky.WHEN JUDGING WHETHER YOU’VE LEARNED SOMETHING:What your brain will do: Your brain will confuse performance and learning. If you seem to recite something from memory — even though you aren’t really drawing on memory — your brain will conclude that you’ve studied enough.How to outsmart your brain: You need to test your knowledge without any other support to your performance. The easiest way to do that is to mimic the conditions of the exam.In this chapter we’ll look at three ways that people can be deceived about their learning when testing themselves, and I’ll describe self-tests you can do to get better information about what you really know.Tip #42Be Clear About What It Means to “Know” SomethingIn his Confessions, written about the year 400, Saint Augustine notes, “If no one questions me, I know; if I want to explain it to those who question me, I don’t know.”This distinction is timeless. Every instructor has had a conversation with a student that goes something like this:Student: I can’t understand how I could have gotten such a low grade. I studied so hard, and I know that I knew everything! Some of the questions seemed really ambiguous to me.Instructor: But you knew everything…Student: Yes!Instructor: So, for example, you’d be comfortable explaining the different mechanisms of forgetting.Student: For sure.Instructor: Okay, so why don’t you describe the main theories of forgetting we talked about.Student: Okay. There’s a stimulus and a response. And if the stimulus is not connected to the response….wait…no…yes, that’s right, if the stimulus gets cut off from the response, or wait, not cut off…um…well….I know it, I just can’t explain it.This student is using the word “know” differently than instructors do. The student is thinking “when we first started studying how forgetting works, it made no sense to me. I didn’t understand the textbook chapter and I didn’t understand the lecture. But I went over the reading really carefully, and a friend from class explained some of the concepts in a different way, and now when I hear the theories of forgetting, it all makes perfect sense.”You can see why the student feels they understand; they ARE much farther along than they were. Following along when someone else discusses an idea is partway to the “understand” that instructors expect. But it’s not enough. Being ready for a test means being able to explain content yourself, not just understanding it when someone else explains it.This situation is a good example of the difference between performance and learning. My student is noting his performance: “I’m following this discussion really well, and a few days ago it would have been really confusing!” He’s not considering that this performance does not necessarily signify complete learning.Unfortunately, the way that many people study leads them to exactly this mistaken perception of what they know. Let’s see how that happens.In one sentence: “Knowing” doesn’t mean being able to understand an explanation, it means being able to explain to others.Tip #43Rereading Does Not Help MemoryImagine you’re taking a business school course called “Innovation.” You attend a lecture on wearable technology — clothing and jewelry that collect and store physical information like heartrate or body temperature. It’s pretty interesting, and you have little trouble following it. The next time the class meets, the professor starts to deliver exactly the same lecture. A nervous titter runs through the room, which the professor ignores. Soon, someone raises their hand and points out that he already gave this lecture. The professor says “yes, but it’s important material, so it’s worth repeating.” He proceeds to give a presentation identical to the previous one: same slide deck, same anecdotes, same “spontaneous” jokes.What would you think?If you’re like me, you would think this was a big waste of your time. I’d be thinking “yes, yes, you said that last time. I know all this, I’m not learning anything.”Now, do I know the content the speaker is reviewing? Well, yes and no. On the one hand, I know I have heard it before, and that judgement is based on my memory of the previous lecture. In that sense I “know” it. But if I tried to provide a summary of what he said it wouldn’t be very good.Many memory researchers distinguish between two ways that you can pull information out of memory. One method is very rapid and requires very little attention, but it can provide only limited information; it identifies whether or not something is familiar. It tells you whether you’ve encountered something before, but not anything associated with it, nor where or when you encountered it. Another memory process can provide information associated with the object, but this process requires attention, and it operates more slowly.These two types of memory probably ring a bell. Sometimes you’ll see someone on the street and the familiarity process tells you “you know this person!” So you call on the other process for more information: what is this person’s name and how do I know them? That second process may deliver nothing — you have no information about their name, how you know them, or anything else. That doesn’t make you feel less certain that you’ve seen them before.In Tip #30 I mentioned that rereading is one of the most common study techniques, and I pointed out that it’s not an effective way to commit something to memory — you should think about meaning, and rereading doesn’t guarantee that.Here we consider another reason that rereading is bad idea. Rereading misleads you into thinking “I know this.” Rereading is like going to the lecture on wearable tech for the second time. When you’re rereading, you’re thinking “yes, yes, I’ve seen all this before. This is totally familiar.” But that’s just it — the sense of “knowing” you’re getting is from the memory process that assesses whether or not you’ve seen something before. You’re right, you’ve seen it before, but knowing you’ve seen it before is not the same as being able to talk about or analyze the content. And the more you reread, the more the process that assesses familiarity tells you “you’ve seen this before!”To be clear, rereading is desirable for the purpose of comprehension. If you read something and didn’t understand it, give it another try. But rereading is a bad way to commit something to memory. It’s bad enough that it doesn’t help memory much, but in addition it makes you believe your knowledge of the content is improving.So, what can you do to get a more accurate assessment of how your studying is going?In one sentence: Rereading boosts familiarity, giving you a false sense that you have mastered content, but being familiar with something doesn’t mean you can recall it from memory and provide other, related information, which is exactly what you need to do for an examination.