Made to Stick (34 page)

“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.

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.

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:

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 contains much more data!

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.

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).