When I began teaching introductory biology at a highly selective university, I didn't expect to find myself giving a failing grade to the valedictorian of a top science and math high school. This wasn't an anomaly. As I continued to see bright, motivated students struggle in my course, I asked myself, "Are they doing something wrong, or am I?" It turns out we both were.

There are some obvious reasons why successful high school students sometimes drop the ball when they get to college. One may be that the brightest students can excel in high school without ever being seriously challenged. Never having had to work for good grades, these students can find themselves at a loss in college, where both workloads and expectations ramp up dramatically. On the flip side, bright students may have put considerable effort into building a portfolio they think will be attractive to selective colleges and universities. These students have taken extra classes, participated in countless activities, performed community service—in short, they have worked hard at resumé building. There's nothing inherently wrong with this strategy, except that it leads some students to see admission to college as an endpoint, not a beginning. Unfortunately, these students arrive on campus thinking they can now relax, having reached their goal of acceptance into a top program.

My failing valedictorian, however, suffered from neither of these problems. This student, like many others I've seen stumble academically in my course, came with well-honed study skills and a healthy motivation to work hard and excel. The problem was simply that he had a poor notion of what it means to know something in science. This is a challenge both my students and I have had to work to overcome.

It is a surprising fact that the majority of students entering my introductory biology class see science as a collection of established facts to be mastered. It's understandable that they should think so. They say that an introductory biology course introduces more vocabulary than a typical first language course; whether true or not, the point is well taken. And it can be hard to avoid introducing myriad facts when discussing kidney function, DNA replication, or how skeletal systems work, for example. I'm also told (although I'm no expert in this area) that high school students are good at being asked to memorize lists of things as a way to foster learning. Regardless of whether this last point is valid, it's nonetheless the case that many students—even the brightest—think that the way to succeed in their first college-level science course is to master facts.

The trouble is that memorizing details is not the way biologists think or work. As a professional biologist, my research isn't enhanced by my ability to rattle off facts. If I forget a detail, or even a major result, I look it up. What is important is that I understand the current questions and how I might go about addressing them. The same is true for anyone who needs to understand how science affects our daily lives. Once in college, students need to adopt a different way of thinking about science and, correspondingly, a different way of learning.

Making this transition is not always easy, and it depends as much on the teacher as it does on the student. Students might have to give up academic strategies that served them well in high school, they have to be willing to experiment with new ways of thinking about material, and they have to appreciate that evaluation in college is different—not just harder, but different. Teachers, for their part, need to provide clear guidance to students to help them with this transition, and this can be hard as well. The unfortunate truth is that it's easier to create lectures that are litanies of facts, and write exam questions that demand little more than simple recall.

What can be done? From a teacher's point of view, the first part of the equation is to communicate at the outset that students may have to think and work differently. One technique I've found particularly effective is to administer a first exam after only two or three lectures. This provides students with an early opportunity to learn how they will be evaluated and to calibrate how they are doing. Another technique I've found useful is to emphasize writing. All my exams, even in my large introductory class, are based on essay responses to problems that test students' conceptual understanding of material rather than their ability to remember things. I also include longer papers, not just lab reports, in the mix of assignments, asking students to develop synthetic arguments about the topics we explore in class. Although it's not easy to incorporate writing into a large introductory science course, it's well worth the effort.

How material is presented across the semester also can assist students with the transition to a more conceptual approach to science. In my experience, a key to success is to organize the syllabus by unifying principles as a way to help students build a conceptual framework. I structure my college course around three broad themes: (1) information and evolution, (2) development and homeostasis, and (3) energy and resources. We look at how living systems work from each of these perspectives in turn, progressing along levels of organization—from molecules to the biosphere—in each case. This approach allows me to connect easily backward and forward to other material in the syllabus, and it requires students to look at sets of "facts" from different perspectives.

Of course, emphasizing how we know something, by examining critical experiments, for example, is a time-tested way to emphasize conceptual understanding. When possible, I take a slightly different approach to this method, explaining what scientists thought they had established as fact some years ago and then explaining how the "facts" have changed in light of subsequent research. 

I know of no magic bullet to make students embrace science as a way of thinking rather than memorizing. It is challenging even for some of the brightest students to make this transition, and it is hard work for teachers to help them do so. But this is a challenge all educators must face. As science in general—and biology in particular—increasingly affects our everyday lives, it has become imperative that students understand not just what is known, but also what it means to think like a scientist.