10. How We Organize Knowledge - The Structure of the Disciplines
Linda Darling-Hammond: Every teacher knows that there is always too much to teach. How do you decide, subject by subject, what's most important? How can you help your students to understand the big ideas of the disciplines they are studying? How can you get them to think and act like historians, mathematicians, or scientists?
I'm Linda Darling-Hammond, and that's our challenge for this session of The Learning Classroom.
Every discipline has a set of big ideas that are connected to each other and provide the glue that holds the subject area together. These include ideas like ratio and proportion, balance, and equilibrium in mathematics. In biology, we might think of major themes like evolution, adaptation, and the environment. Each discipline also uses particular methods of study that reflect how knowledge is built in that field; for example, scientists do experiments, and historians evaluate historical evidence from different perspectives. To really master a discipline, students need to understand what the big ideas are and how they are connected. If they learn to think like experts in that field, their learning will be much more efficient.
Lee S. Shulman, Ph.D., President, Carnegie Foundation for the Advancement of Teaching: If I'm a physician, and I'm doing an examination of you, I don't just randomly say, "Let me look at your nose, how's your toe?" I have a structure; it's the structure of the human body and its organ systems, so I will systematically check the gastro-intestinal tract. I will check the respiratory system, the cardiovascular system, the neurological, right? Because, not only does that give me a structure for moving through the examination, it also structures my memory for any signs or symptoms that I encounter, that may be relevant to diagnosing what you have. So, every time we call something a subject matter, I would say, we call it that because it has some principle of organization that connects the ideas with one another that gives them some kind of order, some sort of meaningfulness, and it's like a code.
Linda Darling-Hammond: Julie Helber, a fourth grade teacher at Paddock Elementary School, helps her students to think and act like scientists and mathematicians as they learn about static electricity and fractions. She guides them through their inquiries by modeling the steps that experts follow in those fields. And then she gives them an opportunity to practice doing what scientists and mathematicians do.
Julie Helber: The students are experiencing a first hand investigation with electricity, so they're actually working with materials and figuring out which materials are static and which materials are not static in several trials and experiments.
Later we studied a second hand observation where the students looked at a notebook test, text from a particular student. And we read through the notebook text together to make some more meaning of what we were learning about static electricity, and we really tried to utilize the text and draw on what we already knew about static electricity to make some conclusions or some hypotheses about static electricity.
Julie Helber: The value in setting up the experiment this way, by allowing the students to investigate something that they might not have clear and concrete directions for there's a lot of value in it. And what I see is the most valuable is that the students are constructing meaning by actually using these materials in a way that they have chosen, so I haven't determined how they are going to use the materials and told them exactly what to do. Because I want them to err in what they are doing. I want them to see that they've tested or tried something that doesn't work, because that's really when they learn.
If I tell them how to do it, it's not likely they're going to remember it later. But if they actually learned it while they were doing it, it is likely that they would remember it later.
When there are a variety of opinions regarding a particular topic really, I think that's the meat of teaching. The students interacting with each other, or I saying "Well, I disagree with another student," is probably the best thing that can happen in my classroom.
Lee Shulman: The notion of structure in mathematics is, is probably one of the most obvious ones. Mathematics is a field where most people who teach mathematics will readily understand the notion that there are certain kinds of structures. There's a notion of balance. There's a notion of equilibrium. There are notions of ratio and proportion that just keep on coming up again and again and again and whether you're doing primary arithmetic or you're doing algebra, those notions return, repeat themselves and you get a sense of how these organizations really make sense of the subject.
Julie Helber: I always offer lots of options for the students to demonstrate what they know. If they need to come up today we were doing a math lesson, and somebody said, "Can I come up there and show you?"
Julie Helber: It's very helpful for students to hear another student explaining why they arrived at a particular answer, because it may not have been the way that they were thinking.
And so by hearing how somebody else is thinking, and it goes back to me modeling how I'm thinking about things, and to maybe change their of way of thinking or to expand the way that they think.
Linda Darling-Hammond: Did you notice how Julie tried to ensure that her students would understand not only the content they were studying, but also the process of experimentation that is central to science and the search for patterns that is at the heart of mathematics?
Tenth grade biology teacher Mary Edmunds helps her students understand cell biology by first connecting the issues of disease to the drama of the science fiction novel Andromeda Strain. She then engages them in the scientific method, so they can examine the features of cell membranes for themselves.
Mary Edmunds: Adolescents have to have hands-on investigations. They have to feel like they're a part of the learning process. They have to be able to take ownership of their own learning and they have to be able to feel that they're a part of the learning and that they can take it out into the world and utilize it. Especially urban youth. Urban youth need to understand that they can do it. They have the tools. They are scientists, and that they can go on, and they can become a big part of this world. And the way you do that is for them to see relevance. So how do, how do you get them to see relevance in cells? They have to know that they're made of cells. They have to know that the anthrax scare was not beyond their ability to cure. They have to know that bacteria can be grown, but that they have the scientific ability and the knowledge to destroy it. But they have to know the internal structure of a cell in order for them to take that knowledge out into the real world and solve any problems.
Mary Edmunds: Students love to be called scientists. I mean, I like to think of myself as a scientist. And if we, if I tell them that you are now a scientist, you're working on an investigation, they're really more interested in it. When they put a lab coat on, a whole new aura comes over them that this is really important, that this is really scientific.
Mary Edmunds: You see in the classroom when I ask the students how would you get the membrane initially, that a lot of them thought, "Well, I'll boil the egg," because they took their past experiences. They boil the egg, they peel it off, the membrane's right there. But I had to get them to understand that this is a living cell, and a living cell has cyto-cell it has cytoplasm (she corrects herself) that surrounds the nucleus, so you can't do that, so what are you going to do?
Mary Edmunds: They have to feel secure in making a mistake and not thinking that they're gonna be ridiculed by me or the other students in the classroom, and they have to be able to take chances. I, I don't know everything. And the kids can ask me something, and if I don't know it, and I tell them, you know, I'm gonna look it up, they feel more secure with me asking them questions and them not knowing the answers. But the best thing to do is to go around and catch it. Catch them while they're doing it and get, get them to think about it.
Mary Edmunds: And see, I had the students decide how to dissolve it. And then that made them interested. If I would've just said, "Okay, today you are going to dissolve the membrane of an, of an egg in vinegar," they would've said, "Okay," today. And if I would've asked them two days later, "What did you dissolve? What, what acid did you use?" They would say, "I don't know. Whatever you told us to." But see, now if I asked them, they would say, "vinegar." And I would say why? "Because the pH is low enough to dissolve the membrane, to dissolve the eggshell without effecting the membrane." That's why I did that.
A couple of the groups broke their egg, accidentally, and they thought, "Oh, the experiment is now a disaster." But that's, I wanted them to understand that that happens to scientists. That there's limitations in life, but the scientific word is a limitation.
Mary Edmunds: It was a perfect opportunity for them to see the consistency of the membrane and to see, they can't see the pores. They cannot see the pores, but they're microscopic.
Well, they, they read that, or they learned that in some past experience that we've done, because I didn't lecture to that. So that, that was a learning experience for them.
Mary Edmunds: I think it's important for them to take the idea of cells to cellular membrane and then how the, the different solutions effect the passage across the membrane.
Problem solving is, is so essential in life. If, if students do not know how to problem solve, they're not gonna be able to make it in college.
But when I get them to problem solve, and I can get them to problem solve, that's where, that's where it all comes together.
Linda Darling-Hammond: Mary's students were able to solve both a fictional and a real life problem by working together using the scientific process. But what if Mary were teaching history instead, where the process of "finding the truth" is not so clear cut?
Lee Shulman: Let's just take it for a given that experiment is a great idea in science. And now we start learning history. Well, how do you do an experiment in history? We then suddenly realize that that's not the way you do history. We don't have, we can't put one historical period in an experimental group and another one in a control group and see what the difference is. But we're still doing comparisons. We're still trying to create evidence. I mean there's certain ideas that do cut across notions of description, of analysis, careful, careful observation, notions of what is the evidence for your claim, notions of theory. But the fundamental process of experimentation, which is at the heart of work in science, has no real analogy in history, if what you mean by experiment is that the scientist is controlling conditions and studying what happens under conditions that she herself has controlled. So what does a historian have to do? The historian in some sense has to look for comparisons where, if you will, nature has made experiments, not scientists.
Linda Darling-Hammmond: Avram Barlowe, a 12th grade history teacher at the Urban Academy, confronts this challenge every day. He has his students read the primary source materials for the period they are studying, so that they can explore the events and opinions of the time and understand the perspectives that shaped historical decisions. He focuses on central ideas like governance and human rights, and he raises essential questions like: Who should govern? And why?
Avram Barlowe: What I asked them to do was to look at that material and ah, to actually look at the text of these laws and decide for themselves what they thought the laws were designed to do, why they thought they were created, how they would have been defended by the people who wrote them. And you'll see, you saw in the classroom there were multiple interpretations of that. And the discussion hinges upon multiple interpretations and meaning of these codes through the looking at the evidence that the meaning presented.
Avram Barlowe: Um, when we respond to the arguments, we respond with them on the basis of the evidence, and when we present them, we present evidence to support them.
Avram Barlowe: The evidence is always central. And what's your evidence and how do you, what, how do we analyze a piece of evidence? So there was an exchange there where that happened. Um, where a kid had not read the material beforehand, was sort of glancing through it as we spoke, and he was making some arguments, and then some other kids would say, wait a second go back to the text. You're making generalizations about this.
Avram Barlowe: I'm really trying to help frame a discussion for them so the inquiry can deepen, and we can get to deeper levels of evidence and argument. And that's basically what's going on, it's an exchange of ideas there. It's not a willy-nilly exchange of ideas; it's an exchange of ideas that's happening within the framework of an inquiry that's rooted in questions that I, that I, that I've designed.
Avram Barlowe: They're beginning to answer things like, they're, they're looking at the question of the freed men after the war in the context of, of the Emancipation Proclamation, Lincoln's role, the slaves self-emancipation. They're building on what they already know, so there's an intellectual growth I think that, that, that you can see.
Lee Shulman: What's really important as teachers teach different disciplines to students is for the students to appreciate that there are certain kinds of ideas like description, like analysis, like careful observation, like evidence, inference and theory, if you will, that are useful across disciplines. But there are other ways in which very important methods of work in one discipline just don't show up in another discipline. And I think history and science make a lovely contrast here.
History and literature also make a lovely contrast.
There are different canons that we use for determining whether it's a good novel, or a bad novel and they're not the same as the ones we use for determining whether something is good history or bad history unless we're gonna use the novel for teaching people history. And so here again, understanding the differences in what counts as evidence and what counts as knowing a subject between subjects becomes terribly important for teachers to understand, and in turn, for students to understand.
Linda Darling-Hammond: Julie Helber, Mary Edmunds and Avram Barlowe teach the central ideas of their subject matters while they also teach their students the skills necessary to learn on their own. By helping their students to think and act like experts in each field, they're not just giving them fish, they're teaching them how to catch them a skill that will keep their students nourished intellectually for the rest of their lives.
This is The Learning Classroom. Thanks for watching.
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