by Dan Heath
Once you’ve found the core of your lesson, you’ll need to explain it as simply as you can. To make explanations simpler, you should anchor them in concepts that students already know. By anchoring, you use the knowledge they already have as a platform for new learning. In the late nineteenth century, when the automobile was introduced, it was often called a “horseless carriage.” Automobile makers were anchoring in the concept of a “carriage,” which was common knowledge. As another example, in the “Simple” chapter, we discussed the classic Bohr model of an atom. Teachers often explain it like this:
“Electrons orbit the nucleus the way that planets orbit the sun.” They’re anchoring the Bohr model in knowledge the students already have. Using an analogy is an easy way to anchor a new concept. Bjorn Holdt, a high school teacher in South Africa who teaches a Java programming class, was having a hard time communicating the concept of “variables.” So he came up with an analogy: “Variables are just like cups. They are containers that hold some information.” Each student was given a different type of cup. Glass mugs were able to store only numbers. Beer mugs were allowed to store only text. Coffee mugs could store only “true” and “false.” Contents were never allowed to be mixed—for instance, you couldn’t put a number in a coffee mug. (This limitation illustrated a procedure called “type-safe programming.”) Holdt reported that this analogy helped students understand the concept of a variable more quickly and retain it longer. He said that he was frequently able to untangle misunderstandings by explaining things in terms of the coffee cup or the glass mug.
To make an idea simple, then, first find the core of your lesson, then anchor it in knowledge that your students already have.
REMINDERS: “Simple” concepts from the book that are useful for teachers: Generative analogies. Complexity through schemas The Pomelo Schema. The inverted pyramid Burying the Lead.
Unexpected
William B. Yeats once said, “Education is not filling a bucket, but lighting a fire.” That’s a great sentiment, but how do you light the fire of your students to learn about, say, mammalian physiology? Well, you might take a hint from a book we recently spotted in the bookstore that had this title: Why Do Men Have Nipples? We suspect that ten seconds ago you weren’t pondering mammalian physiology. But when you see this question and realize that you don’t have a ready explanation, it makes you wonder. It sparks curiosity, and that’s the beginning of a fire.
In the “Unexpected” chapter, we discuss George Loewenstein’s gap theory of curiosity, which says that curiosity comes from a gap between what we know and what we want to know. Teachers can make powerful use of this technique. For instance, a physics teacher in Colorado asked his students, “Have you ever noticed that in the winter your car tires look a little flat? So where did the air go?” The book Freakonomics also makes great use of curiosity gaps: “Why do so many drug dealers live with their moms?”
Curiosity can provide the fuel for a series of lessons. The San Diego Zoo teaches a summer program in which junior high school students learn to do DNA analysis. Maggie Reinbold, the designer of the program, introduced the topic with a mystery worthy of a CSI episode: An animal has been sneaking into the food bin at the petting zoo and eating the animals’ food stores. The goats, deprived of their vittles, are losing weight. (And you do not want your goats getting anorexic.) The students must investigate and figure out which animal is doing the thieving.
Two nights earlier, the food-thieving culprit left a few threads of black hair on the feeding station. Unfortunately, this narrows down the suspects only a little. The lineup of black-haired animals includes a goat, a pig, a sheep, and a horse. Only DNA analysis can reveal the truth about the thief. Over the course of the week, Reinbold used this mystery to teach her students a whole mini-course in molecular biology. Students used dissecting microscopes to extract some cells for DNA analysis. They learned about the Nobel Prize—winning Polymerase Chain Reaction (PCR) procedure that can be used to turn a few copies of DNA into billions of copies, and then they put on their white lab coats and consulted with zoo researchers about how to conduct a PCR analysis on the zoo’s machine. They used gel electrophoresis to compare the DNA pattern of the thief with DNA patterns of pigs, goats, sheep, and horses. After enough legwork, they discover that the villain was…Ed the Pony. (But don’t expect a tearful confession.)
That’s the value of curiosity in a nutshell: It can hold kids’ attention for a week as they tackle serious science. To make it work in your lessons, use knowledge gaps and the power of mystery.
REMINDERS: “Unexpected” concepts from the book that are useful for teachers: Curiosity gaps The “Gap Theory” of Curiosity. Professor Cialdini’s mystery of Saturn’s rings The Mystery of the Rings. Nora Ephron’s journalism teacher Journalism 101.
Concrete
In math, students often struggle with the notion of a “function.” What exactly is a function, and what is meant by its strange “f(x)” notation, which looks like nothing else that students have seen before?
It seems so abstract, so mysterious. So Diana Virgo, a math teacher at the Loudoun Academy of Science in Virginia, gives students a more real-world experience with functions. She brings a bunch of chirping crickets into the classroom and poses a question: What will happen to the crickets’ chirping as the temperature changes? Will it get faster or slower? And might the crickets’ reaction be so predictable that we can actually graph a function that predicts how fast they’ll chirp? Our function would be like a little machine: You feed in a temperature (say, 85 degrees) and out pops the rate of chirping (say, sixty chirps per minute).
So the class runs the experiment: The crickets chirp. The students count the chirps. Virgo changes the temperature. The crickets, undoubtedly puzzled by the weather, chirp differently. The students count again. And soon the class has gathered a bunch of data that can be plugged into a software package, which generates the predictive function. It turns out that the hotter it is, the faster the crickets chirp—and it’s predictable! Suddenly, the idea of a function makes sense—it’s been grounded in reality. Students have personally experienced the entire context—where functions come from, how they’re constructed, and how they can be used. (As a side note, Virgo also warns her students that human judgment is always indispensable. For instance, if you plug into the function the temperature “1,000 degrees,” it’ll predict a really, really fast rate of chirping! Sadly, though, at 1,000 degrees crickets don’t chirp at all.)
The cricket function is an example of making a concept concrete—avoiding abstraction and conceptual language and grounding an idea in sensory reality. It’s the difference between reading about a wine (“bold but balanced”) and tasting it. The more sensory “hooks” we can put into an idea, the better it will stick.
An eighth-grade teacher named Sabrina Richardson helped students “see” punctuation by using macaroni. Richardson described her exercise:
The students were given cards with sentences that were missing punctuation like quotation marks, periods, exclamation points, commas, apostrophes. The students were divided into groups of two and three and were given baggies that contained elbow macaroni, small macaroni shells, and ritoni. The students were asked to place the pieces of macaroni in the correct place in the sentence. For example, they were given the sentence:
Jackie shouted Gwen come back here
The students had to use the elbow macaroni as commas and quotation marks and a small macaroni shell as a period. They could combine the ritoni and the small macaroni shell for an exclamation point. I knew that a lot of my students were confused about whether the comma went inside or outside the quotation marks, so this gave all of them a chance to “see” the correct way to punctuate quotations. Once they were finished, they knew the sentence would read: Jackie shouted, “Gwen, come back here!”
Concrete, sensory experiences etch ideas into our brain—think of how much easier it is to remember a song than a credit card number, even though a song contain
s much more data!
REMINDERS: “Concrete” concepts from the book that are useful for teachers: Math instruction in Asia (Understanding Subtraction). The Velcro theory of memory. Jane Elliott’s elementary-school simulation of prejudice (Brown Eyes, Blue Eyes).
Credible
Amy Hyett, an American literature teacher at Brookline High School in Boston, teaches a unit on transcendentalism. She says that when students read Thoreau, and learn how much time he spent alone in the wilderness, they have a common reaction: Er, why would he do that? So, in the spirit of building empathy, she gives them an unorthodox assignment: Spend thirty minutes alone in nature. No cell phone. No iPod. No pet companions. No Game Boy. Just you and the great outdoors.
Hyett says, “It’s quite amazing, because almost every student has an illuminating experience. They are surprised by how much the experience moves them. Even the most skeptical students come away with a deeper understanding of transcendentalism and nature.”
For an idea to stick, it needs to be credible. YouTube-era students don’t find it credible that hanging out outside, alone, could be conducive to great thinking. So how do you combat their skepticism? You let them see for themselves. Sometimes you have to see something, or experience it, to believe it. For instance, you might not believe that adding Mentos candy to a two-liter bottle of soda would cause a volcanic eruption that sends soda spewing ten to fifteen feet from the bottle. But you’d believe it if you saw it. (In the meantime, just Google it for a laugh.) Lots of science-lab experiments operate on this principle: See for yourself. (Notice, too, that labs are pedagogically useful for other reasons: They are often unexpected—“Look, the chemicals turn bright blue when mixed!” And they are always concrete—instead of talking about a phenomenon, you’re seeing it or producing it.)
Another technique for making ideas credible is to use statistics—but perhaps not in the way you’d expect. It’s difficult to make a statistic stick. Numbers tend to slide easily in one ear and out the other. But the relationships illustrated by statistics can be quite sticky. Tony Pratt, a fourth-grade teacher in the New Orleans Recovery School District, was teaching his students the basics of probability, and as an example he told them that they had a really, really small probability of winning the lottery. The odds are one in millions. But this statistic is so extreme that it fuzzes our brains. Our brains can’t easily distinguish between “one in millions” and “one in tens of thousands,” even though there’s an enormous gap there! So Pratt grounded the probability in a relationship. He said, “You’re more likely to be struck by lightning than to win the lottery.” That amazed the students—it gave them an intuition for just how rare it is to win. In fact, several of them rushed home to tell their families.
One student, Jarred, relayed his story: “I saw my uncle buying lottery tickets last night. I told him that he was more likely to be struck by lightning than he was to win the lottery and that buying lottery tickets was a bad idea because of probability.”
“What did he say?”
“He told me to get the f____out of his face.”
Some people are more resistant to sticky ideas than others.
REMINDERS: “Credible” concepts from the book that are useful for teachers: The NBA and AIDS education (Rookie Orientation). The bacteria-chugging scientist. Using the human-scale principle.
Emotion
Bart Millar, an American history teacher at Lincoln High School in Portland, Oregon, was having a hard time getting his students to care about the Civil War. “We talked about the weaponry, the tactics, the strategy, and so on. The students were respectful, but not much beyond that,” he said.
Determined to do better, he went to the National Archives website and downloaded photos of battlefield surgeons and their surgical tents. He presented these to his students and asked them to imagine the sounds of war: the explosions, the rustle of uniforms, the occasional eerie quiet. And the smells of war: dust, gunpowder, blood, excrement. This activity, which brought sensory information into a “dry” subject, was beautifully concrete. But Millar had one more surprise in store for the students.
In a corner of the room was a table covered with a tarp. Millar whisked away the tarp to reveal two stopwatches, two thick-looking bones, and two handsaws. The bones were cow legs procured from a local butcher that approximated the weight and thickness of a human femur. Two student volunteers were asked to play the role of a battlefield surgeon, forced to amputate a soldier’s leg in the hope of saving his life. Their mission: Saw through bone forcefully and quickly—after all, at the time there was very little anesthesia.
Millar says, “The entire lesson only took about fifteen minutes, but ten years later students who stop in to say hi still talk about that lesson.” And it’s not hard to see why: He found a way to make his students care, to give them a peek into the brutal realities of war.
That’s what emotion does for an idea—it makes people care. It makes people feel something. In some science departments, during the lesson on “lab safety,” instructors will do something shocking: They’ll take some of the acid that the students will be handling and use it to dissolve a cow eyeball. A lot of students shudder when they see the demonstration. They feel something. (It should also be noted that some students, mostly male, think it’s “cool.”) Lab safety “dos and don’ts” don’t grab you in the gut, but a dissolving eyeball sure does.
And that’s the role of emotion in making ideas sticky: to transform the idea from something that’s analytical or abstract or theoretical and make it hit the students in the gut (or the heart).
REMINDERS: “Emotional” concepts from the book that are useful for teachers: The dilution of “sportsmanship” (The Case of “Sportsmanship”). Why study algebra? (The Need for Algebra and Maslow’s Basement). Voters who vote against their self-interest (The Popcorn Popper and Political Science).
Story
Have you ever noticed, when you teach, that the moment you start sharing a personal story with your students, they instantly snap to attention? You understand the value of stories. But some teachers don’t insert many stories into their lessons, because they’re worried that they don’t have gripping stories to tell, or that they aren’t good storytellers. So maybe it’s worth identifying which kinds of stories are effective in making ideas stick. The answer is this: virtually any kind.
The stories don’t have to be dramatic, they don’t have to be captivating, and they don’t have to be very entertaining. The story form itself does most of the heavy lifting—even a boring story will be stickier than a set of facts. Several times in the book, we’ve seen the power of a story to keep students engaged—remember the “Safe Night Out” entrepreneurial story, used to teach accounting? It was so effective that it made students more likely to major in accounting. Or recall Cialdini’s story of the race to solve the mystery of Saturn’s rings. Just a few pages back, we discussed the tale of the petting-zoo food thief. None of these stories were Oscar material, but they were irresistible to students.
Stories can be useful for discipline as well as academics. Greg Kim, a ninth-grade English teacher at Eagle Rock High School, used a story to reach an unruly student, whom we’ll call John. John was a well-meaning student who just couldn’t seem to stop socializing or horsing around in class. Kim talked to him several times and tried to explain that his behavior was disrupting the class and endangering his grade. Often, John would take these talks to heart and change his behavior—for a few days. Making matters worse, on the rare days that he did behave well, John would say, “Aren’t you proud of me? I was good today.”
Kim said, “I tried to talk to him about consistency, and how he needed to be focused every day. But John looked at me, confused….
In his mind, being good sometimes was being good always.” Kim struggled with the problem of how to get John to understand the need for consistent behavior. He tried analogies like “one step forward two steps back.” But all he got from John was a blank look.
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nbsp; Later, Kim was discussing the situation with another teacher who had taught John in English class the previous year. The teacher had similar problems with John and, indeed, the only time John had shone was when he wrote a personal narrative about how he’d lost thirty pounds. Suddenly, Kim realized what he should do:
The next day I spoke to John about his behavioral inconsistency and compared it to a friend of mine who had struggled with weight loss. The friend had decided to go on a diet and exercise regimen to lose weight. The first day, he was good. He ate right and exercised, but the second day he broke his diet and didn’t exercise. The next day he was good, but the following two days he was bad again. And so it went, on and on. I told John that my friend would beg for my approval by letting me know he was good on the days that he was, but weeks later he had somehow gained weight. I told John this story and asked if he knew what the problem was. He laughed and said the answer was obvious. With a big smile, John said, “He didn’t stick to his diet every day.” I stared at him and watched the realization engulf him, and his smile became thoughtful.