New Methods Teach Science By Observation, Hypothesis

Those just starting out are being trained to think like scientists to keep more of them interested and unlikely to switch majors Standing before the 2,000 students enrolled in his introductory chemistry course at Purdue University in West Lafayette, Ind., chemist George Bodner mixes two flasks of chemicals. Through the exhaustive exchange of questions and answers that follows, Bodner forces this throng of young scientists to "invent" the concept of molarity long before any of them has read in a textbook how to determine the molecular concentration of a substance in a solution. "My goal in chemistry is to try to help students learn the ability to think the way chemists think," says Bodner (see Close-Up on page 8). "Most of what I teach consists of styles of problems: How do you recognize what a problem is? How do you know where to start and when you have solved it successfully? "The facts of science are no more intrinsically interesting than the dates in history. The excitement comes in understanding what you can discover, and why it is important." Bodner's approach reflects a trend at United States colleges and universities in teaching first-year science. Scientists and students alike say they are fed up with professors and textbooks that expect students to accumulate facts and passively accept hoary opinions. In their place are alternatives similar to Bodner's. The approaches carry many names--hands-on science, experiential science, and constructing science through cooperative learning. But they all aim to teach students in the classroom and lab to engage in science through observation and hypothesis. Ignoring traditional boundaries that separate disciplines and disregarding texts that parcel out similar concepts to different chapters, students learn to see the relationship between principles or phenomena they have discovered, such as the conservation of energy or the growth of a plant. The goal is to produce more students who are excited by science. When George Bodner was an undergraduate majoring in chemistry, the thing he resented most was the lab requirement. "Nothing I did in my lab courses seemed valuable, because people told me how to do it," remembers Bodner, now a professor of education and chemistry at Purdue University. "It was the same as watching Julia Child: all cookbook." Bodner had switched his major from history because he thought he would earn more money when he graduated. But he discovered that he wasn't so crazy about science, either, and he remained a C student. "Then, when I was a junior," he recalls, "somebody let me into a real research lab, and I said, `This is fun. I may not be very good at it, but I enjoy it.' That's when I became a scientist and not just a chemistry major." Bodner has never lost that enthusiasm. Ten years ago he established a group at Purdue to study the application of learning theory to chemistry. Two years later he set up a graduate program in chemistry education to teach scientists to bring the joy of science to their pupils. "The high of doing science, when it goes right, is better than any drug ever made," he says. "I may not be able to lead my students through a religious conversion, but I want to give them the experience of what a scientist does." Bodner recalls how, when he taught at Stevens College in Columbia, Mo., he expected his organic chemistry students to synthesize the new compounds he needed for his own experiments. "They didn't know how to make the compounds," he says. "The information wasn't in their textbooks, so they had to go into the technical literature and look it up. In a process that went on over a period of weeks, these kids got a feeling for what it is to do science." The approach seems to be working. Since Bodner started letting students act like scientists, he says, their grades have improved and he has far fewer students who, like himself in his early college years, are content to simply major in chemistry. --D.M. "Though it's too early for statistics, I've talked to many educators who already see an impact," says Jack Lohmann, project director in the new Division of Undergraduate Science, Engineering, and Mathematics Education within the Education and Human Resources Directorate at the National Science Foundation. "My own observation is that students [exposed to such an approach] are more capable earlier in their academic careers of understanding lab equipment, physical phenomena, and science concepts than are their counterparts in the traditional courses." An interest in nontraditional ways to teach science is not new. But experts say the idea really began to catch fire about five years ago. "Teaching undergraduates to do science the way a scientist does it has grown phenomenally since people first began to talk about it in the mid-1980s," says Jerry Mohrig, a chemist at Carleton College in Northfield, Minn. It was then, he says, that the national Council on Undergraduate Research, of which he is president, began "to make the case for nontraditional science in Washington and around the country." The council found that the country was ready to listen. NSF had just released a disturbing and widely read report that universities were not producing enough scientists to meet anticipated demand in the next two decades. Among other things, the report called for more hands-on and experimental science. Many educators have recently been spurred into finding alternative science teaching methods by one frightening figure: 40 percent of students who say they plan to major in science abandon the sciences after their first college course in the field, according to the findings of a 1989 policy research analysis group at NSF. Most of the students are bored, say education experts, and many of them are intimidated by science. Instead of mindlessly solving textbook word problems, students would be better off learning by doing, they say. That study validated what more and more professors had already started to do. Many have torn up their lecture notes or thrown away their textbooks. Undergraduates may devote half a semester to exploring every subtlety of atomic structure, instead of being served up one lecture and problem set to teach them key vocabulary words. As a result, students are forced to think for themselves, advocates of the hands-on approach say. By carefully analyzing how data are manipulated in a published research article, or by failing repeatedly before successfully isolating a chemical substance, they learn how to ask questions and to put facts in context. "A lot of students are turned off by science," says NSF's Lohmann. "Courses have become too focused on the knowledge of science rather than the process and experience of science. There is a public concern about the number of students who are bored, and we want to show them how to enjoy science." In May the division expects to award $8.5 million to institutions with innovative programs to improve the undergraduate curriculum. But not everyone thinks that hands-on instruction is the answer to the problem of keeping students interested in science. Many educators worry that the approach is a fad that could cause students to miss a large part of their science education. Says Sheila Tobias, an independent researcher based in Tucson, Ariz., "I am a little bit nervous about hands-on science, which has the smell of a buzzword. People are jumping on it as if it will solve all problems, for all people, at all times." The new technique also requires more time and teachers than many universities want to contribute, others say. And because success depends so heavily on the abilities of the individual teacher, the methods are hard to define and difficult to pass along. But other college and university teachers say fewer students would be bored by science if they were taught to think like scientists. Merle Bruno, a neurophysiologist at Hampshire College in Amherst, Mass., tells the 20 undergraduates in her introductory bioscience class not to study their biology texts. Instead, they go straight to the journals and learn to decipher a primary research article. "What we teach them at Hampshire is to keep learning and demanding answers, something most of us don't learn until we are graduate students," she says. "This approach really turns them on to understand cellular mechanisms or the epidemiology of AIDS." Those in the hands-on science movement are also trying to spread the word to others. Earlier this month, Project Kaleidoscope, a year-old organization dedicated to strengthening college science, held a colloquium at the National Academy of Sciences in Washington, D.C., to outline a plan to increase experiential and investigative learning programs. This week, members of the Alliance for Undergraduate Education, a five-year-old group representing 16 major universities, will gather during the annual meeting of the American Association for the Advancement of Science to discuss practical ways to set up new science courses emphasizing hands-on science. To help pay for many of these new classes, the Howard Hughes Medical Institute (HHMI), as well as NSF, will be passing out tens of millions of dollars in grants this year, much of it for hands-on programs. Lohmann says he's amazed by the recent surge of interest in the hands-on approach: "There are 730 grant requests sitting in my office. Many of them are applying this new teaching philosophy. They are making the learning of science mirror the way science is actually practiced. I'm convinced that if we had put this [request for more hands-on science] out five years ago, we would not have gotten this response." Since 1988 HHMI has awarded $91 million to liberal arts colleges and universities to support innovations in teaching. This year it will be passing out an additional $31 million, says HHMI vice president Joseph Perpich, much of it to support "tutorials, seminars, and mentors" that allow students to become more engaged in science. Real-world experience can also teach students about the cooperation essential to lab science, says Paul Williams, a plant pathologist and executive director for the Center for Biology Education at the University of Wisconsin in Madison. His first-year science students learn about photosynthesis and energy transfer as they cultivate a special breed of fast-growing plants. "I break them into groups of three," he says. "I de-emphasize facts; they must come up with a scientific process together to ascertain a fact or reach a conclusion." Even physics, which relies heavily on equations and abstract concepts, is open to this experiential approach, scientists say. The 60 science majors in freshman physics at Rose-Hulman Institute of Technology in Terre Haute, Ind., do physics on a graphics computer, plotting a trajectory and then repeatedly launching a projectile until the particle just skirts a distant hill on the screen. In more conventional physics classes, says their professor, electrical engineer Jeffrey Froyd, students would just hand in an equation for the trajectory. "As a scientist you begin through experience to develop judgment for when your answers are right and when they are not," says Froyd. "My students can stand back and say, `What is it I am trying to do here?' Too often, students emerge from freshman science with a collection of tiny boxes, and when they have a physics problem they say, `Okay, which box does it fit into?' We try to give them concepts, instead, rather than have them break things down into categories of problems." Students in classes such as Froyd's may well understand science better and enjoy it more. But it's not clear that more of them end up with advanced degrees in science--an important goal of those who fund these programs. Part of the reason is that most programs are only a couple of years old. Their students haven't had time to pass through the system. Nor has anyone surveyed colleges and universities to catalog these kinds of courses and determine their success, although speakers at the Project Kaleidoscope meeting this month hoped to address that question. The successful techniques that science professors use are also difficult to quantify and pass on to others. Too often one professor's successful teaching method, such as hands-on science, is ineffective when applied by another. "Can a very good idea be translated into a mass product without losing its magic?" Tobias asks. "After living through `new math,' I have grave doubts." Another obstacle is the fact that classes are exhausting for both teacher and student. Less thinking is required, educators acknowledge, when a class is structured around lecturing and note taking. "When I engage students in arguments, it takes a lot more personal attention than it did when I used to just lecture," says Charles Holbrow, who has taught physics at Colgate University in Hamilton, N.Y., for 25 years and who has written an alternative textbook for introductory physics. "You have to kick the student out of his passive mode. One student complained to me, `You're trying to make us think, and in high school we only had to stuff numbers into formulas.' " Though Holbrow believes his new introductory classes produce students who understand physics better than the ones in his lecture classes did, he does not believe he is persuading more students to become physicists. Why not? They see how hard physicists have to work, he says. Still, for a growing number of professors, there's no substitute for the real thing in science. "The students in my class invent molarity," says Bodner. "And anything you create you are more likely to remember. It is not something you accept on the basis of authority. Nor have my students simply learned a set of facts and equations. I have allowed them to build on prior knowledge and to see the relationships between what they learned two weeks ago--moles--and what they learned today--molarity."

New Methods Teach Science By Observation, Hypothesis

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