LYNDEN, Washington—Never underestimate the value of an unexpected outcome. That's not a rule you'll find in any physics textbook, but it's a lesson that longtime science teacher Don McQuarrie has taken to heart. At Lynden High School in the northwestern corner of Washington, McQuarrie takes advantage of teachable moments when students are surprised by what they see.

McQuarrie coaches his students through a learning cycle of prediction, observation, and comparison, based in part on RealTime Physics* education resources developed by Professor David Sokoloff at the University of Oregon. To make the observation part of the cycle more compelling, McQuarrie often has students use probeware and computer interfaces to gather measurements.

For example, he typically introduces a discussion about force by staging a classroom demonstration. Two model cars are loaded with different weights, outfitted with force probes, and then crashed into each other. As McQuarrie explains: "Students tend to predict that the heavier car will hit with more force. But measurements show that the force is equal. That causes them to wonder why. Those 'aha!' moments, getting them to think, is what I'm after."

In chemistry class, McQuarrie conducts a demonstration about freezing water. "Using probes, we can take a temperature reading every tenth of a second." Once the temperature drops below zero, the teacher stirs the container full of freezing water. "Students see that the temperature scoots back up." Again they want to know why, and that gives McQuarrie the perfect opener to introduce the concept of crystal nucleation.

McQuarrie, a 30-year teaching veteran, has been using probes in the classroom for more than a decade. Incorporating the technology into active learning helps students gain a good grasp of fundamental concepts, he says, so that they are well prepared to pursue more advanced studies. "I hear back from them after they go to the university. They tell me they're doing the same kinds of things in their college classes as we did in high school. My students gain a better conceptual sense of science."

One project has emerged as a perennial favorite. Each winter, McQuarrie escorts his physics students to a nearby ski area for an active lesson in "The Physics of Skiing." Before they zoom down the slopes, students strap on accelerometers so that they can record their rate of acceleration. Non-skiers aren't left out of the adventure. The ski area provides them with beginner lessons and equipment rentals. Their prediction? A slower acceleration down the slopes, but lasting memories about how to learn science.