A Quality Lesson

by Michael Rossman

        It's science day for the fourth grade. I'm hardly in the door before the kids swarm over me, demanding, "What did you bring today?" Usually it's a dead possum, or something else bulky and spectacular. Today all I've got is a little coffee-can that rattles, and a sly smile that warns them to expect a curve ball.

        "Hands off! Don't open it yet!" I wait until they settle in a circle on the rug. "Okay. Who remembers my last name?" We call each other by first names here. Titters rise, as they realize how few know my full name. "So what would you say, if someone wanted to know about your science teacher?"

        "His name's Michael?" Annie ventures. "He's good!" Ralph calls out from the back.

        "Um-hum, um-hum," I mutter, noncommittal, "keep going."

        The descriptive phrases flow quickly. "He's blue-eyed." "He gets excited a lot." "He wipes chalk all over his pants."

        Finally I ask: "So what's more important to know, my name, or my qualities?" They come to quick agreement: it's the qualities that matter. We talk about how often we forget someone's name and yet remember the person quite clearly -- by his or her qualities, of face and form, speech and motion, character.

        Having practiced the idea on human ground, I steer the lesson towards physical science and perception, and my coffee-can. "Now, what would happen if we knew the names of things like glass and water, but not their qualities?" An eruption of images -- trying to eat a glass, stepping on a lake -- convinces us that life would be a helpless chaos. "And if we knew the qualities of things but not their names?" Clearly we could get by, though communication might be a problem.

        "Okay," I announce, "here's the rules of our game. Number One: ZAP!, you've just forgotten the names of everything. All you can name are the qualities of things. Anyone who says a noun aloud has to go stand on their head. Number Two: Even though some of these sticks are actually a little bit thinner or shorter, or rough on the tip, you're going to pretend that they're all exactly the same size and shape. Those are the only rules. Now go to it," I say, as I open the can and spread its contents on the carpet. "No shoving! There's enough for all."

        I step back, as they scramble to examine my handiwork. Indeed there are enough, I was up half the night cutting them -- 128 little round rods, each three inches long, cut from lengths of quarter-inch stock of various materials: aluminum, brass, steel, wood, lucite, a black plastic, carbon, and glass. I wound up with 16 sets of rods of eight different substances, jumbled now on the carpet in a random array, of qualities incarnate.

        At first the children just try to grasp what's there, with their hands and minds. Soon someone says confidently, "This one's wood," and another asks, of a brass rod, "Is this gold?" I clown it up in rebuking them, to drive home the rule that we know no names of things now. It takes a few reminders, for the noun habit's hard to shake; but most take easily to the spirit of the game.

        As their interest peaks, I move on. "Okay now, here's the task. Pick a partner to make a team, and gather a complete set of rods. Your set should include one of each different kind of rod in the pile. Signal me when you're done." They team up easily and fall to it, gathering their rods busily. There's more than enough of each kind, so nothing's scarce. No one asks me how many kinds there are.

        In five minutes even the slowest teams are done, with little puzzling over the matter. I note the results, without yet announcing them. Seven teams have come up with six rods apiece; two have only five; two found seven. But before they can compare their sets, I move to the blackboard, tapping the chalk sharply to call their attention, as I get ready to make a list.

        "Now tell me how you put your sets together. How could you tell one kind of rod from another?"

        "Well, they're different ..." Amanda begins.

        "Be specific."

        "This one is brown and this one is black," she says, offering a wooden and a charcoal rod.

        "All right. So they're different in some quality. What's the name of the quality?"

        "Color?"

        "Sound right?" I ask the class. They agree, and I write it on the board. "Let's have another. Are there pieces you can't tell apart by color?"

        Josh offers the charcoal and black plastic rods. "This one's shiny."

        I write shine below color. "Are there rods you can't tell apart by color and shine?" Ralph and John, who found seven different rods, flourish their aluminum and steel ones in triumph, moving the others to paw chagrined through the rods still on the floor. "And in what quality do these rods differ?"

        "Heaviness," they say confidently -- inviting me to remind them of the distinction between weight and density, before adding density to the list and asking for more qualities.

        As the list grows, so does my delight as I recognize how rich and instructive so simple an inquiry with such simple materials can be. Color is the only quality they can name precisely and understand well. Every other quality they recognize, like heaviness, demands more definition than they can give, invites an excursion simultaneously into richer and more precise language, and into more precise thought.

        Shine requires them to distinguish between glowing and reflecting. "You can see through this clear one" leads us to define transparent, translucent, opaque. The subtle differences in hue between steel and aluminum remain beyond their power to describe. But some differences in the way the rods feel to the touch are obvious, and coaching helps them to distinguish the textural qualities rough/smooth from the frictional qualities sticky/slippery, by which glass differs from clear plastic.

        Everyone notices that each kind of rod has a different sound (or tone), for they tinkle in a quiet random music as we sort them over. Yet until I suggest it, no child observes that the sticks have different smells, or wonders whether they might have different tastes (as they do, though sanitation forbids our proving this together.) Their embarrassment yields to interest, as I tell them how inhibited our own culture is in using these senses, compared to some others. Then we return to naming qualities.

        By now, we're down to individual insights. Annie finds she can dent a wooden rod with a fingernail. "This one bends a little!" cries Josh. I add hardness and flexible/rigid to the list, and ask, "What would happen if you bent one really far?" They imagine the results with a glass rod, a brass one; and choose breaking strength as their name for the quality. I introduce them to the idea of "non-destructive testing", and compliment them for practicing it so far. Then I ask them to imagine destructive tests that might reveal other qualities. They imagine hammering the rods; I help them to clarify the ideas of brittleness and malleability that emerge.

        And here the trail ends. When they leave this realm, of qualities perceived directly through their senses and bodies, and pass over into the indirect and conceptual realm, their ability to identify more qualities fails completely. One child wonders if the metal rods are magnetic, but doesn't ask to test them. No one rubs a rod to see if it's a static (electricity) generator, or wonders whether any rods are burnable or poisonous, or whether some might be meltable or dissolvable in water, or conductors of electricity.

        This sharp division, between the sorts of qualities the children think of and the sorts they fail to think of, is striking evidence -- but of what? A narrow reader of Piaget might say it just shows that eleven-year-olds haven't yet made the developmental transition from concrete/instrumental thinking to abstract/analytic thought. But I think the failure may be due less to their immaturity in grasping abstractions -- for color itself is a profound abstraction -- than to their lack of experience with more sophisticated ways of engaging with materials, and to their not yet having developed the habit of seeking to make connections between the different things they already know.

        For indeed, when the connections are suggested, the children do understand many more abstract qualities, and how they apply here. Every quality above is already familiar to them from our experiments, they groan with chagrin as I list them on the board: conductor, burnable, ... I tell them that science has discovered a hundred more subtle ways to distinguish the qualities of things. Listing a few on the board -- fluorescence, heat capacity, radioactivity, magnetic permeability -- I leave the terms to stand as promises of penetrable mysteries, as I return to the familiar realm of our direct senses, where vivid lessons await us.

        Carla's team is the only one with two clear rods in its set. I ask why. "They magnify differently," says Carla shyly. There are three more obvious ways to tell glass from plastic that no one noticed, so she deserves congratulations. Everyone scrambles among the loose clear rods, to test them on lines of print. She's right, it's obvious, once you pay attention to what you're seeing.

        I postpone the discussion of optics, to focus on how they'd handled their perceptions. Thinking back, most realize that they too had sensed some subtle difference in the visual qualities of these transparent objects, but had let the perception go without trying to pin it down. And why? "I just thought they all were glass," says Nathan, wonderingly.

        "Assumed," I correct, "You assumed they were glass. So why did every team but Carla's come up with a glass rod, and not a plastic one?" Mulling it over, they realize that after assuming all the clear rods were glass, they had paid unconscious attention to their different refractive qualities anyway -- choosing the prettier rods, that glowed more brightly with bent light.

        "Okay. I'll tell you the moral this time," I say, "and you tell me the next time." I write it down:

        ASSUMING THAT YOU KNOW WHAT SOMETHING IS, CAN KEEP YOU FROM RECOGNIZING WHAT IT IS (UNDERSTANDING ITS QUALITIES.)

        Then I return to the confused tactile perceptions -- of warmth, sweatiness, etc. -- that many children ventured when we started naming qualities. "Let's do a little experiment." I tell them each to choose two rods, one metal and one non-metal (but not glass.) "Be careful to pick rods that haven't been handled recently. When I say GO, grab one in the palm of each hand, shut your eyes so you can concentrate on feeling, feel them both for a few seconds, and then drop them. Ready? GO!" They comply. "What did you feel?"

        A babble of voices as they open their eyes. Most agree: there's a difference in temperature. "Okay, get set to do it again. This time do it until you think you understand the qualities you feel, and what's going on. GO!" They focus again; it's a slow thirty seconds before the last eyes open. "So what's going on?"

        "The metal rod is colder," Josh exclaims, backed by a babble of agreement. I cup my hand to my ear, listening for a contrary opinion. "Uh-oh," says Nathan, as silence settles on the circle, "Does mean we blew it again? But how come? It felt colder to everyone."

        "Well, let's sort out what happened. Remember what heat is? Heat is ..."

        "Molecules-in-motion," they sing out, in a scrap of melody rehearsed as often as the concept. "And hotter-is-faster," a few think to add.

        "Bravo! Now, if the metal rod really was colder, the other rod must have been hotter before you touched it, right? So how'd it get hot? Where's the blowtorch?" We puzzle it out: all the sticks had been together in the same can since last night, were on the same carpet now, exposed to the same conditions; if one were hotter yesterday, it'd be cool by now, and vice-versa.

        "So they must have been the same temperature!" Annie exclaims.

        "Before you grabbed them, yes. Now let's look at what happened then. Which was warmer, your hand or the rod?" They agree: the hand. "So which molecules were hitting faster, the rod's on the hand's, or vice-versa?"

        "Vice-versa," says Nathan, intently.

        "So the rod's molecules that got bumped started moving ...?"

        "Faster," several chime together.

        "And the hand's molecules moved ..."

        "Slower." By now it's a ragged chorus, preparing for what's coming.

        "So which way was the heat energy flowing?"

        "From the hand to the rod," Josh says, in dawning comprehension. "But ..."

        "So as soon as you grabbed a rod it started getting ..."

        "Warmer!"

        "... and your hand got ..."

        "Colder!" The chorus is in synch now, hot on the track.

        "And which hand got coldest?"

        "The metal hand!"

        "So metal ..."

        Nathan pounces on the quality: "It takes heat away faster!" But it's Stephanie who faces the contradiction. "So the metal rod was warmer when we felt it. It was warmer, not colder, not the same!"

        "Uh-huh," I agree calmly. "We call this heat conductivity." I add the term in cramped letters to the bottom of the list. Then I turn, and hit them with the crusher, the low blow. "By the way, folks -- how come you all thought the metal rods were colder? Just what was it that you were feeling?"

        Silence settles, electric, until Stephanie cries, "My hands! My own hands!"

        I let the reversal sink in. It's stunning, it's almost too simple to comprehend. We go through it again to make sure, as if exploring how a robot works. Here is the heat sensor. It takes its own temperature. When something makes it hot, it sends a signal, which the brain interprets to mean that the something is hot. The brain's often right -- but really, what we measure is what's happening inside us, not what's out there.

        All our senses work this way; but the details will wait, for there's enough to think about today. What seems colder is hotter, what seems outside is inside -- such inversions are bewildering even to adults, the kids deserve a break. Some day, if they keep on in science, they'll learn how deeply this sort of realization has influenced modern physics and philosophy. But for now, they need some way to tie it down, and I summon them to try.

        "So it's your turn to tell me: what's the moral?" They puzzle it over, it's not as clear. Somehow they tricked themselves again, into misreading the evidence of their senses -- but how?

        To sort it out precisely takes an adult's capacities for abstraction. They don't even try, but go straight for the heart of the matter, the emotional and instrumental core. They put it two ways. After I help them boil their raw efforts down. I chalk both on the board, in a box labeled SAVE:

        IF YOU MISTAKE YOUR OWN REACTIONS FOR THE THING ITSELF, YOU CAN GET AWFULLY CONFUSED.

        IF YOU DON'T UNDERSTAND HOW YOUR OWN RESPONSES ARE INVOLVED, YOU CAN'T MAKE SENSE OF WHAT YOU SEE OR FEEL.

        "All right. Now let's finish our task. How many different rods did each team gather the first time?" Almost all report six. "And why did you stop at six? What other assumption did you make?" I help them to think back, to recognize that by listening casually to each other, they'd formed a quick consensus that there were only six substances, which kept them each from seeking further to observe and interpret the rods' differences.

        "Hey, but you didn't really let us compare our sets," protests Nathan. "We'd have come up with eight, all together."

        "Hey, but the trouble with the way you did it would've been the same, right? Now use your own senses and minds, and gather a complete set."

        "How many are there?"

        "That's for me to know and you to find out," I say, as staunchly as I can since they already know. "Get to it." The rest are already rummaging in the common pile, comparing rods, taking them outside to the sunlight, bouncing them, rubbing them to see if they leave marks. Mostly what they discover is new ways to tell apart things they already know to be different. But some teams have gathered nine or ten rods by the time I call a halt and ask for their reports.

        "Okay, show me," I say, openly skeptical. Most of the extra rods are duplicates, their differences more wishful than actual. But two stand up to our common scrutiny -- for the charcoal rods are cut from stock of two different densities, and the wooden ones show two consistently different patterns of grain.

        The children crow with delight as I confess with delight that I hadn't noticed the differences myself, cutting them last night. "Though grain's a pretty trivial difference," I add to Annie, who had recognized it, and who tends to think quite highly of herself.

        "Hey, you said the different parts of a tree-trunk had different strengths," says Josh, who thinks highly of her too.

        "Absolutely. You're both right, it's a real difference. Let's have the rods back now, it's time to go." They start passing handsfull forward to the can, as I add, "I guess it takes a girl to see the difference in the pretty textures, and a boy to think of the difference in strength, right?"

        Among children of this town, that's like saying "a baby sealskin coat is pretty"; the class hoots with derision.

        "But really, if someone's sensitive, isn't she a girl? If someone likes science, isn't he a boy? Doesn't that seem clear? And if it seems clear, isn't it glass?" Nathan and Annie brighten, as they grasp the point, but the others are slower. I repeat it. "If it's clear, isn't it glass?"

        "You can't know who someone is, from just one quality!" says Annie, triumphantly.

        "Didn't everyone know I was a good science teacher right away, when I cut up that dead possum?"

        "No way!" says Stephanie. "I was afraid of you, I thought you were angry because you yelled a lot."

        "And I thought you probably didn't like science, because you didn't say anything in class for weeks. I guess it was just another one of those assumptions, hey?" I say, sliding the last rods into the can and sealing its lid. "Okay, see you next week. Remember not to take hot for cold."

        And we're done for today. There are many ways to extend the inquiry, to learn more of how our prejudices, assumptions, and reactions keep us from recognizing and encountering the distinct qualities that make each person who s/he is. But I'm happy with this beginning -- for the connection between the scientific, the personal, and the social lessons is grounded in their own experience, rather than in rhetoric, and may enrich their lives.

        Walking home, I fondle my small clanking can as if it were the treasure it is, a cradle full of fragments of the world for our encounter. I make a mental can the same size, to file the morals of the lesson away, but they won't fit, spill over untidily.

        Through our inquiry, the children increased their stock of basic physical concepts, developed their abilities to observe and discriminate, and practiced some critical and interpretive skills. All this fits in the standard dimensions of a science lesson. Yet the lesson is as much about themselves as about science: about how each sees privately, about how we see each other. And more, it's about the confluence of these dimensions of learning, in integral experience. But where can I file what it's for, why I did it, what it means?

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