Editor's note: This is an extended version of the News Scan story "Expert Education," from the June 2010 Scientific American.

DEATH VALLEY, CALIF. —The dozen students and scientists spread over an area called Furnace Creek looked like cyborgs in floppy hats scrabbling over the boulders. Before hammering chips off rocks, they inspected them with magnifying lenses held up next to eyeglasses sporting miniature cameras and infrared lights.

A seasoned geologist could tease out a history of earthshaking clashes here from evidence in the terrain—a break in a steep grey slope, for instance, suggested a fault at work fracturing the landscape. The aim now of the cameras was to see how researchers' eyes darted across this scene, to figure out how experienced minds unconsciously scan the world for clues that point the way to discoveries.

On this expedition out in Death Valley—where driest, hottest and lowest places on the continent are found — the scientists are investigating how geologists view landscapes, but such research could very well delve into how detectives analyze crime scenes or soldiers look for camouflaged targets or distinguish between friend and foe when storming rooms. Researchers then perhaps could train neophytes with virtual reality displays that simulate environments of interest.

"We know a lot about how to educate people on facts, but we know almost nothing about how to educate people on acquiring perceptual skills other than lots of repetition, which can be very time-consuming and expensive," says cognitive scientist Robert Jacobs at the University of Rochester. "It would be great to develop more effective training procedures."

The key here is a wearable eye-tracking device that can monitor what people look at in a natural environment. It consists of two lightweight video cameras mounted on eyeglass frames—one pointed at what a person is seeing, the other pointed at the person's right eye, tracking its movements with the help of a little infrared LED that shines an invisible beam onto the eye.

Two camcorders in a slim backpack record video from the cameras, data that eye-tracking programs then process later. "Most other eye-tracking devices do eye-tracking simultaneously, but then people are carrying around computers and it's much more cumbersome," says imaging scientist Jeff Pelz at the Rochester Institute of Technology. "Ours is an incredibly stripped-down design."

The novice and seasoned geologists from the University of Rochester have gone out with the eye-trackers about four times a day over their two-week field trip across California, which took them from San Francisco by the San Andreas Fault through the snowy Sierra Nevada near Yosemite National Park here to the harshest area of the U.S. "Death Valley is a great place, where one can really see active geology first-hand — forces that are shaping the crust of the earth," says geophysicist John Tarduno of the University of Rochester. "Most people think of Death Valley as this big hole because it's below sea level, and that's true at the heart of it, but right adjacent is an 11,000-foot mountain."

Nature doesn't like such elevation differences right next to one another; erosion tends to even things out. "The fact we have a valley today hints at active processes to maintain that difference," Tarduno explains. "It's conclusions like these that we hope to see students reach by themselves."

As with almost all field trips, unexpected troubles arose, such as the sandstorm that engulfed Death Valley on the first day, sending the group to a campground at the snowline of Mt. Whitney, the highest point in the contiguous 48 states. The desert is trouble in other ways — the glint of the sun off the eye can confuse the eye-tracking software, which is why those wearing eye-trackers all had to don ungainly wide-brimmed sun hats that have been the objects of much ridicule. Even so, the software loses track of gaze in maybe 10 to 15 percent of the video frames the cameras record, a problem future algorithms will hopefully fix, says Jason Babcock, president of Positive Science, who built the eye-trackers.

Aside from the eye-trackers, the researchers also used a robot-operated camera to take hundreds of high-resolution photos of the areas, which can later get stitched together for panoramic images displayed on giant wrap-around screens, as well as a video system consisting of six cameras, whose feeds are woven together to create a seamless hemispheric movie.

"The hope is we verify that student geologists in the field and those surrounded by these virtual environments view formations the same way so we can use simulations to train novices on dozens of virtual field trips, cutting down on the costs of travel and equipment to make better use of actual trips," says imaging scientist Mitchell Rosen at the Rochester Institute of Technology. "My greatest hope is that a geologist can sit down in a virtual field trip and make observations he or she didn't or couldn't make out in the field, by putting scenes next to each other, or zooming in, or performing other kinds of analyses not available out there."

Those flashes of discovery are what the researchers are seeking to record now. At the Long Valley Caldera, Tarduno quizzed students about the lava flows they saw and the curve of surrounding landmasses until they realized they were standing in a dormant supervolcano roughly 20 miles long and 11 miles wide now covered in snow. "I was really excited at that instant," student Shannon Moss recalls. "I saw this circle we were in and it just came to me." An otherwise fleeting moment now captured by the eye-trackers.