Americans have wrung their hands in recent years over the state of science education in their country, with that bedrock subject -- physics -- a particular concern. Only a relatively few high school students, barely 20 percent, ever get exposed to physics. And when those few move on, they often meet an early Waterloo in college-level introductory physics.
Delo Mook, a physics professor at Dartmouth College, has decided to put this latter phenomena under his microscope, so to speak. He has developed a passion for finding out why students, many of whom study hard and arrive here with strong secondary-school backgrounds, often trip over his course and veer off for some field other than science or engineering.
His method: turn the failing students into consultants who can help him come up with alternative ways of conveying the basic concepts of physics.
''Ten years ago,'' Professor Mook says, he would have told a failing student: ''I did everything I could. Maybe you're just not cut out for this.'' Now the wispy-haired, round-faced physics professor believes that response is weak, if not dishonest.
He speaks of a ''realization, on my part, that in a sense I'd been swindling a lot of students.'' They come to him, as ''customers,'' and say ''teach me physics.'' He and other professors hand the students textbooks based on an education gained from similar textbooks, Mook says, and ''if they don't get it, we fail them.''
Some 345,000 students a year in four-year colleges that offer a degree in physics qualify for Mook's definition of a ''customer,'' according to statistics compiled by the American Institute of Physics. Of these, about 30,000 are students at least tentatively aiming at a career in engineering or the physical sciences. Their introductory courses are of the tougher, calculus-based variety taught by Mook.
Such classes are often taught by professors or teaching assistants ''interested in teaching, more than in students' learning,'' observes Patrick Mulvey, a researcher with the Institute of Physics in College Park, Maryland. It's common, he says, for half the students who originally enroll in these classes to be gone by midterm. ''[Instructors] think they're weeding out, getting the cream of the crop.''
The truth ignored by that approach, Mook contends, is that ''different people learn in different ways.'' By working very closely with students on the brink of failing his course, he tries to prepare ''a smorgasbord'' of ways physics concepts can be grasped, greatly increasing a student's chances of passing. A student's success or failure Mook asserts, should be ''a shared responsibility.''
Mook's approach was an academic lifesaver for Cathy Harris, a Dartmouth sophomore from Grangeville, Idaho. ''I was so cocky when I came here,'' she says. ''I thought anyone could get an A if they really worked hard enough. How wrong I was!''
Ms. Harris was on the verge of dropping out of Mook's course when she came in to talk with him. She told him of her goal of becoming an engineer, and he volunteered to tutor her.
Eventually Harris joined a small corps of erstwhile physics failures hired by Mook, using what scarce funds he can scrape together, to help him redesign his course in a way that embraces multiple approaches to physics. Harris, for example, had a difficult time learning from the text, no matter how many hours she spent poring over it. She and Mook came up with some ways of graphically or visually portraying concepts.
''He'd ask 'Why are you stuck?' as soon as I had a problem,'' Harris says, describing her one-on-one sessions with the professor. ''Then he'd pick up something and demonstrate a concept right there.''
Another student who is working with Mook is Dorrie Bright, from Nashville, Tenn. She has also come up with graphic aids for students prone to trip over certain physics or math concepts. She explains, for example, her way of likening partial derivatives to ''a slice of a three-dimensional picture.''
Ms. Bright, who describes herself as ''a physics major -- so far,'' says Mook's style of teaching is well known among students. ''I heard his name my first day on campus,'' she says. She heard it from two other female physics majors she happened to meet.
The majority of students Mook has worked with to improve his course are women, which is more a function of inherent sexism in the way science is taught than a reflection on their ability to learn physics, he says. Many male students, he adds, simply aren't willing to admit they're not getting it. Both men and women, he feels, are being helped by the teaching aids he's building into his course.
He recalls one student who said she always stumbled over the Greek letters pervasive in physics and math. She suggested providing a simple listing of the letters and their pronunciations. That's now one of dozens of aids students in Mook's class can call up on their personal computers through Dartmouth's campus-wide electronic network. Since every student here is required to have a computer, access to such background material on courses is virtually universal.
Still, some students fail, either because they just don't put in the work or because -- despite all Mook's efforts -- physics remains a mystery to them. But the professor himself is more committed than ever to unveiling the mystery of how students learn, which he says is even more engrossing than the theoretical physics he spent years researching.
He hasn't been able to keep in touch with every student that has taken advantage of his effort to open a wider door to learning physics. He does, however, pull out some letters from former students who thank him for keeping them from bailing out of a career in science or technology.
Mook thinks his attempt to rethink physics instruction is still in the early stages. ''I'm working at it,'' he ''but I'm not real good at it yet.''