Testing the boundaries of teaching science

Sandhya Sinha

Sandhya Sinha checks whether her E. coli bacteria have grown successfully, part of her work in the junior year project lab.

Johnny Clore

Junior Johnny Clore checks for the success of a chemical reaction in a gel, one step in creating novel DNA fragments for gene replacement.

At left: Lab instructor Manuel Llinás discusses the progress of junior Anita Gupta’s project as she works on her experiments.

Below left: Will McFaul works on a lab assignment with Eileen Zhuang as part of their freshman year ISC coursework.

Photos: Denise Applewhite

Bottom left: Members of the class of 2008, the first to take ISC coursework, say they have bonded closely during the experience, and decided last year to have sweatshirts printed to commemorate their time together.

Photo: Eric Wieschaus

From the March 12, 2007, Princeton Weekly Bulletin

Some of Princeton's most scientifically talented undergraduates are dedicating their years on campus to more than learning how to conduct experiments. They have elected to be part of a grand experiment themselves — one that is attracting attention nationwide.

The students are enrolled in Princeton's Integrated Science Curriculum (ISC), a three-year-old effort to dramatically reorganize the manner in which scientific ideas are introduced to students. The goal is to prepare graduates for careers in a scientific world that requires a new level of expertise: next-generation scientists who have mastered their own discipline and can work closely with specialists from other fields to solve problems as a team.

"Everyone knows there's a problem with introductory science education," said David Botstein, director of the Lewis-Sigler Institute for Integrative Genomics and one of the ISC's creators. "Any budding researcher needs a foundation in several fields to be able to work on the most important problems confronting scientists today, but it's hard to do that from the outset. Providing that foundation has required us to create an entirely new set of courses run by faculty from across all these disciplines. It's a stretch for the teachers as much as the students, because even we are still figuring out what it means to teach the relationships among our fields."

While organizers are still refining the curriculum, they already are hosting visits from educators who are interested in what is — and isn't — working.

The students are telling them that the coursework is demanding, but that the program may be succeeding.

"I definitely came away with better problem-solving skills," said Hanlin Tang, a junior who just finished the ISC's fifth semester. "The material has been really challenging, but the enthusiasm of the professors and the bonding among the students has made up for it. And we all got the chance to learn material we wouldn't otherwise have seen."

Anita Gupta and Manuel Llinás

The setup

Tang is one of 18 students who has completed the two-year ISC sequence and the junior year project lab in quantitative and computational biology. The group entered the program when it began in the fall of 2004 and includes 10 molecular biology majors, four physics majors, two computer science majors, and one each from geosciences and electrical engineering.

This intellectual diversity of the initial class has continued with subsequent groups of ISC students, and the number of participants has remained about the same. Twenty sophomores and 17 freshmen are now taking the courses, which are taught by 10 faculty members from chemistry, computer science, molecular biology and physics.

The courses occupy a major portion of the first five semesters any ISC student spends at Princeton. Both semesters of freshman year, as well as the fall semester of junior year, require "double" courses demanding the equivalent of two ordinary classes' time and effort. (Sophomore year requires a "single" course both semesters, each with a standard time commitment.)

Even the course abbreviations have lengthy titles such as CHM/COS/MOL/PHY 233, indicating the breadth of knowledge the faculty is trying to impart. William Bialek, who has taught primarily the freshman course since the ISC began, said the courses are not meant to replace the standard introductory science curriculum, but to introduce science in a novel way.

Will McFaul and Eileen Zhuang

"We want these students to really understand scientific problems — they are not just learning to recite knowledge they've received," he said. "It's an enormous task we've set for them as freshmen, but in the end we hope they come out with the tools all these fields provide for solving problems, as well as an awareness of what motivates a chemist and why, compared to what would interest a physicist looking at the same situation."

Bialek, the John Archibald Wheeler/Battelle Professor in Physics, said that the approach initially shows students that a problem in one field can be addressed by a tool taught in another. However, he said, such a "divide and conquer" approach is just the first step in becoming an interdisciplinary thinker.

"Eventually, simply getting ideas together gives way to actually thinking in the intellectual tradition of all these fields, which might be compared to having a multicultural understanding of the scientific world," he said. "That's how you have to think if you really want to communicate with other specialists."

The first students in the program learned an early lesson in this regard. They jelled quickly as a multidisciplinary study group, each contributing to the team's effort to master the broad subject matter.

"I had to depend on other students, and vice versa," said junior Anita Gupta, a molecular biology major. "I found it hard when we were doing physics-oriented material, but others did when we were doing molecular biology. We weren't competitive at all because we needed each other to study all these subjects at once."

By the numbers

What does it mean to take on several natural sciences simultaneously? Mainly, it turns out, it means learning them by the numbers — literally.

By understanding the mathematical patterns that underlie physical phenomena everywhere in nature, students develop an intuition about the world that can help them approach problems in any classical scientific field.

Developing students' mathematical intuition is one of Botstein's goals, and one that is proving the most challenging to achieve.

"We know what math we'd like students to have, but meshing it with other fields isn't quite where we want it to be as yet," he said. "That's one of the reasons we're committed to providing them with a sounder basis in theory, and have brought in some new faces to help our undergrads think more flexibly about all the disciplines."

Matthias Kaschube and Michael Desai have just begun five-year positions as Lewis-Sigler Fellows at the institute, largely tasked with leading freshmen and sophomores through the math-based coursework.

"The coursework is organized by mathematical theme, not by traditional discipline," said Desai, a 1999 Princeton graduate who completed his Ph.D. in physics at Harvard. "We just gave an exam on what are called probabilistic models, a kind of math that ties up ideas from statistics, physics and several others from chaos theory."

This last subject, though it incorporates a host of complex mathematical ideas, concerns shapes that even the uninitiated readily recognize as beautiful and "natural," such as the outline of a seacoast or the branching patterns of tree leaves. Other, long-familiar shapes are considered as well, such as rounded curves like the Poisson distribution from probability. Once the math behind these shapes is mastered, the students can find them in contexts as varied as animal population change and star distribution in the sky.

Kaschube said that teaching the material this way brings home the difference between his own undergraduate science initiation and the ISC, which is also broadening his own perspective as a scientist.

"This curriculum is nice for scientists of many different backgrounds," said Kaschube, who is applying his own physics education to examining biological systems. "Both Michael and I are physicists, so we're used to doing a lot of math, but I used to think some of these shapes were just weird solutions you'd come across now and then. Eventually you see the Poisson distribution is not just this weird solution to a particular problem, but a pattern you can see in lots of places in nature, like in the activity of brain cells."

Integrated Science Curriculum juniors

The vanguard

The 18 juniors are the self-acknowledged guinea pigs of the program. Some agree that the program has been challenging in the extreme for all involved, though the effort has been equally invigorating.

"It's been rough for both us and the faculty, who are pouring tons of their own effort into the ISC," said Ashley Wolf, a molecular biology major. "It sometimes seems like there are more of them involved than there are students. They collaborate to create amazing lectures. We can tell they all have been thinking for some time that science needs to be taught differently."

Gupta said the professors have been much of what makes the program so worthwhile.

"They have been incredibly accessible to us from the beginning," she said. "It has been obvious that they are excited about this, and that they want it to succeed, even though they are still figuring out how to present all the material effectively."

Nearly everyone said that the camaraderie among the students has been one of the most enjoyable parts of the experience.

"We've bonded well," said Tang, a physics major. "We had barbecues every week together this past summer. We even had sweatshirts made and posed together in them to remind us of our time going through all this. I'm sure I'll keep in contact with everyone when I've graduated."

The bonding among the students also was readily apparent while observing them in the "project lab," the newest and last of the double courses. In December, the students were working with a species of yeast whose genome actually has much in common with the DNA in human cells.

A student can experiment on yeast and get an answer relevant to human biology, and in shorter order — yeast grows much faster than human cells do. But though the students had spent three hours a day, four afternoons a week, working in the basement of the Icahn Lab, there was a palpable sense of urgency in the room as they hurried to finish their efforts before the semester ended.

"These students are all pursuing individual projects, asking whatever questions they like, so long as we think it can be done in the time the semester allows," said Manuel Llinás, an assistant professor of molecular biology and one of the lab instructors. "But they are trying to get the whole picture of the organism. We steer them toward looking at the whole yeast genome, not just little parts of it, and that takes time."

Scrolling across one student's computer screen was a representation of the activity of the yeast's thousands of genes, each of which sends signals for the cell to do more of one task, less of another. The readout looked like multicolored tickertape from a stock exchange, except that the flickering dots formed a nonverbal message only a trained scientist could decipher.

The students milled about, organizing tubes of liquid chemicals and peering at readouts on their monitors. A few quietly discussed their next steps in pairs or trios; another concentrated on her work in apparent solitude. But only apparently — a window on her desktop showed her chatroom conversation with her lab partner, who was only a few dozen feet across the room. Raised voices would distract everyone, and the students, some barely out of their teens, have gained enough knowledge and experience to run a lab on their own.

"These students know what they're doing for the most part by now," said Amy Caudy, another of the five Lewis-Sigler Fellows. "We just offer our experience at times. We're trying to keep mistakes down and progress up."

The end of the beginning

Once the project lab ended, the ISC students finished the run of courses the faculty had prepared for the group as a whole. Though their work as a unit was done, all will continue to take coursework toward their individual majors' graduation requirements, and many will develop junior papers and senior theses based on their ISC work.

Several also will pursue a new qualification, the certificate in quantitative and computational biology. This program will give them specific grounding in ways to observe gene expression's relation to physiology and the evolutionary process, according to Saeed Tavazoie, the associate professor of molecular biology who is directing this aspect of the ISC.

"The certificate is a formalization of the fact that their education isn't limited by the usual breadth of their major," Botstein said. "It will mean that they have a command of these other fields as well."

Their education will have to continue, Botstein said, as will the honing of the Integrated Science Curriculum.

"This will prepare them for their scientific future, but will not be enough on its own," he said. "If the total number of students that goes to graduate school increases by the number of ISC graduates, we will have succeeded."

As for the curriculum, Botstein said that while there will be no radical changes made over the summer, there will be a greater integration of subjects awaiting the incoming freshmen.

"We always intended to have the courses evolve with experience," he said. "Physics will be more evenly spread over the first two years, allowing more biology and chemistry into the first year. Both the faculty and the current ISC students believe this is a good idea."

Botstein also said the faculty plans to contact freshmen sooner than they have in the past so that they are aware of ISC as an option long before they set foot on campus. A new website explaining the curriculum is in development as well.

"We hope these efforts will help us attract more of the right students to the program," he said.