Mixing It Up

Science is becoming more and more an interdisciplinary and multidisciplinary pursuit, but students usually learn each subject in isolation. Recently developed courses at three universities buck this trend and show that it is possible to teach science in an integrated fashion to both science majors and nonscience majors.

"It really is true in the world of research that traditional disciplinary boundaries are no longer so relevant," says Michael H. Hecht, a chemistry professor who is an instructor in an integrated course at Princeton University. "Why don't we teach science the way we actually practice science?"

The three courses, at Harvard University, Princeton, and Columbia University, target widely different audiences and serve different purposes. All students are welcome in Harvard's course, called Life Sciences 1a. The Princeton course caters to a select group of students who can use it to meet the introductory requirements for subsequent classes in biology, chemistry, physics, and computer science. The Columbia course, called Frontiers of Science, is the newest addition to that university's long-established core curriculum. The one thing these courses share is their integrative approach to teaching science.

At Harvard, Life Sciences 1a just finished its first year, in which the semester-long course was offered twice. Five biology and chemistry professors collaborate to teach the class, which fulfills the introductory requirements for biology students and some of the introductory requirements for chemistry students. Once Physical Sciences 1a—currently in the planning stages—is up and running, the combination of the two will fully meet introductory requirements for chemistry students.

Life Sciences 1a is the first step in an effort to revamp the life sciences curriculum at Harvard, says Robert A. Lue, executive director of undergraduate education in molecular and cellular biology and a senior lecturer at the university. The committee that designed the course wanted to introduce students to chemistry and biology in a way that reflects how research is done today.

"The way it's taught is designed to be highly coherent, highly focused on major questions, highly relevant, and very engaging," Lue says. "The energy was unbelievable. Hall B—our largest science center lecture hall—was packed every lecture and the students were full of questions. I've taught here for 20 years, and I've never seen that kind of energy." The participating professors—three from biology and two from chemistry—attend every lecture, randomly distributing themselves among the students.

The professors take a topical approach to biology and chemistry, teaching fundamental concepts from general chemistry, organic chemistry, molecular biology, and cellular biology within the context of HIV and cancer. "We felt that framing these scientific concepts in the context of modern problems facing society would provide a compelling big-picture story to constantly remind students why learning these concepts is essential," says David R. Liu, a chemistry professor on the teaching team. For example, reaction thermodynamics and kinetics are taught in the context of the reaction catalyzed by HIV protease and inhibited by HIV protease inhibitors, and pK_a, pH, and equilibrium are taught using the phosphate group of DNA and the side chains of amino acids as examples.

The professors have designed the lab portion of the course to engage students in modern scientific activities. A staff of 30-35 teaching fellows oversees the labs and associated discussion sections. Each lab section has approximately 15 students. The students do experiments such as the final step in the synthesis of fluvastatin, a cholesterol-lowering drug. Or they analyze students' DNA using the polymerase chain reaction to find genes that correlate with the efficiency of HIV entry into cells.

The course has been quite popular with students. Nearly 500 students took the class the first time it was offered, making it the largest undergraduate science course at Harvard in recent memory—possibly ever. Despite the availability of course materials on the Web, including videos of lectures, students filled the hall for every session. In anticipation of even more students next fall, the class has been scheduled in a space it shouldn't outgrow: Sanders Theatre, which seats nearly 1,200.

Princeton's course has been spearheaded by David Botstein, director of the university's Lewis-Sigler Institute for Integrative Genomics. In designing the new course, "the target for us was that subset of students who are interested in physics, chemistry, and biology for themselves, as opposed to those who are taking introductory physics, chemistry, and biology for some other purpose, as a prerequisite for something else," he says.

He's interested in serving the students who already want to be scientists. "This is an alternative for motivated, risk-taking students who are not afraid of getting a B, provided they learn something," he says.

There are risks involved. The students sign on for a lot of work. During their freshman year, they take a double course that meets for five lectures a week, with labs and small group sessions on top of that. If the class doesn't work for some of the students and they want to drop it, they can find themselves with huge holes in their schedules.

After two years, Botstein is satisfied with the level of sophistication of the class. "For some of the faculty, it was difficult to get their minds around the idea that they could go much faster and much more in depth than they can in their ordinary introductory courses," he says.

The course is evolving and is definitely still an experiment, Botstein says, but he's pleased with the results so far. "We've made more progress faster than we had any right to expect," he says. In the first year, the laboratory portion of the course went more smoothly than the lecture portion, which he attributes to the efforts of Maitreya Dunham and Will Ryu, Lewis-Sigler fellows who had responsibility for implementing the laboratory. "In the planning group, we spent a lot of time thinking about the experiments we would like the students to do," Botstein says. "We came out with these high-concept experiments and these two young scientists really made it work." For example, the students learn about Einstein's theory on Brownian motion and repeat Perrin's experiment using modern equipment to measure the mean free path of plastic fluorescent balls. Then they do simulations of Brownian motion in two dimensions. "Most of this stuff juniors in physics haven't seen," Botstein says.

For the students, most of the introduction to biology occurred in the laboratory, Botstein says. In class they learned the physics, chemistry, and computational skills they would need to understand the biology. "We're raising the bar considerably on the level of hard science that our biologists will have command of and the level of biological and nonphysics understanding that our physicists and computer scientists will have," Botstein says.

At Columbia, all freshmen take the new integrated course as part of that university's famed core curriculum, which is required of all students. David J. Helfand, an astronomy professor, has long thought that science deserves a place in that curriculum. Originally launched in 1919, Columbia's core curriculum, which until recently featured seven courses in the humanities, hadn't changed since 1947. Students were required to take three semesters of science, but they chose from a smorgasbord of offerings that wasn't actually part of the core.

"It struck me that this was rather misguided," Helfand says. "The one great advantage of these core courses is that all students take them at the same time. It extends learning outside the classroom, because they're in their dorm rooms doing exactly the same thing."

Science students recognize the value of including science in the core curriculum, but many of them would like to see separate sections for science and nonscience majors, Helfand says. "We resist that on philosophical grounds because that's not done in the rest of the core," he says.

Helfand first proposed adding a science course to the curriculum in 1982, but it didn't become a reality until 2004, because it took him a long time to get other people to take the idea seriously. Helfand recruited the best lecturers he could, showing political astuteness in the process. "When you've got a Nobel Laureate in physics, Horst St??rmer, teaching in the course and enthusiastic about it, it's really hard for anybody else in the physics department to criticize the course," Helfand says.

The participating professors thought hard about what they wanted the course to accomplish. They didn't want a course focused on science and society or a broad, shallow introduction. Instead, they wanted to show students that science is not a set of facts but a set of approaches. Second, they wanted to instill in the students quantitative reasoning skills, what Helfand calls "scientific habits of mind."

The students develop these habits through topics such as astronomy, climate change, biodiversity, neuroscience, nanoscience, and biophysics. The topics change depending on the professors who are teaching. The lecturers begin with introductory material but quickly reach the point of talking about their current research.

The course is divided into four units, with a different professor teaching each unit. These professors, additional faculty members, and postdoctoral fellows serve as seminar leaders for smaller discussion sections, which have about 20 students each. The university created a Columbia Science Fellows program—postdoctoral scientists supported 70% by the course and 30% by departmental or grant funds—especially for this course.

The intent is to give students the opportunity "to abandon their high-school-cultivated notion that they're not science people" and to realize that "maybe they should consider science," Helfand says. The goal of the class is not necessarily to create more science majors, although he wouldn't object to that outcome. Instead, as a fan of liberal arts education, Helfand would be happy to see humanities majors taking additional science classes beyond the three-semester requirement just because they are interested.

In such integrated courses, professors have to make tough decisions about what to leave in and what to leave out. "We think we cover the vast majority of the essential concepts in general and organic chemistry and molecular and cell biology that students need to go forward into their next courses," Harvard's Liu says. "The goal is to teach them the essential concepts and keep them interested: Get them engaged, spark their curiosity whenever possible, and motivate them to remain dedicated to the natural sciences."

To develop Princeton's curriculum, professors from the participating departments discussed what they consider to be fundamental for any scientist to know, regardless of the field he or she is entering. Many of those fundamentals they teach on a "need to know" basis. "We really believe that we should avoid, if at all possible, 'Learn this now, it's good for you later,' " Botstein says.

One of the biggest challenges for the integrated classes at all three universities is dealing with diverse student backgrounds. "In the same classroom you can have—and the first year this was literally true—the Intel national science winner and people who can't do arithmetic," Columbia's Helfand says. Similarly, Harvard's Lue says, "You may have students who are tremendously strong in the humanities but, based on what their school had available, have weak science backgrounds."

Even in Princeton's class, which enrolls only an elite set of students, professors have to deal with differences in students' preparation in the various scientific disciplines. "Some of them are physics whiz kids and know zero biology or chemistry. Some of them are biology people and know zero physics," Hecht says. "That's a bit tricky because we're teaching them as one group. Today's lecture may be easy for person A and hard for person B; tomorrow's lecture may be the opposite."

The courses deal with this potential problem by providing an extensive support system for the students. For example, Harvard's Life Sciences 1a has a "student study network" that focuses on problem sets and exam preparation. Although taking part in the study networks is not required, many of the students attend the sessions. The professors encourage the more advanced students to help other students who might be struggling. "We made it clear that there's no better way to gauge one's understanding of material than to try to explain it to somebody else," Lue says.

Another challenge is the lack of textbooks and instructional materials available for such classes. At Harvard, they've initially assigned the students two textbooks: "Organic Chemistry" by Paula Yurkanis Bruice and "Essential Cell Biology" by Bruce Alberts et al., but the professors have basically created their own handouts from scratch. "The truth is that there is probably no textbook currently in print that covers the concepts we cover," Liu says.

Each of these courses has been an experiment, and so far each has been successful, on the basis of student feedback. The classes are new enough that more quantitative studies of student performance and choice of major will have to wait until the first groups of students have advanced enough in their programs.

A major reason for the classes' success is the tremendous resources that the universities have thrown behind them. At Harvard, "the resources committed to this course were enormous," Liu says. In addition to the five Harvard faculty and 30 graduate students who serve as the teaching fellows, there are two Ph.D.-level "preceptors" who oversee course logistics and hold review sessions, as well as a dozen undergraduates who lead study networks. "I've never seen a course that has so much support structure for the students," Liu notes.

The Princeton program "has had a huge amount of resources and a huge amount of attention and the top students at Princeton," Hecht says. "When you have resources, attention, excitement, and the top students, you're going to succeed no matter what. Now comes the harder part. The first blush of doing it the first time is behind us, and now we have to make sure that we can sustain it in the long run."

Support provided by Botstein's institute makes it easier for Princeton's course to avoid draining resources from the participating departments. The institute comes equipped not only with lab space but also with positions that are joint appointments with other departments. "I don't actually want to change anything that the departments are doing, and I certainly don't want to cost any resources," he says. "The resources are incremental and I think that is fundamental to what we're doing."

Helfand worried about the stability of Columbia's program from the beginning. "I was determined to make it sustainable," he says. "It was clear that you can get a bunch of people enthusiastic about doing something for a couple of years, but unless you build a structure that is sustainable over a long period of time, it's nice while it lasts, but then it goes away."

Helfand has made sure that Columbia's program doesn't rely on a single group of faculty. "The course can't be identified with individuals," he says. Instead, faculty members rotate in and out of the course. Over the next several semesters, new faculty members will be rotating in. "After about four years, it will be a whole new set of lectures and topics," Helfand says.

Columbia's program will undergo a major test in the 2007-08 academic year, when both of the codirectors, Helfand and biologist Darcy B. Kelley, go on sabbatical. The other participating professors will be left to make sure that the course "still swims" without the directors. "I think it will because we've got a fairly high-level cadre of people who are committed to it," Helfand says.

These classes show that integrated approaches to teaching science can be adapted to a variety of target audiences. The challenge now lies in making sure that they are successful over the long term.