NASHVILLE, Tennessee—In a challenging course like accelerated physics, high school students know that keeping an accurate record of their data is a key to successfully completing a lab. The trouble, admits veteran teacher William Rodriguez at University School of Nashville, is that "students get so focused on writing down the data, they can lose sight of what the numbers represent."

University School of Nashville is an independent school with about 1,000 students in grades K-12. In a recent physics lab having to do with measuring the potential of an electric field at different points, Rodriguez gave his students a chance to gather results using old-fashioned lab methods, and then repeating the lab, using handheld computers rigged with data-collection interface devices. The handhelds "removed much of the difficulties of doing the experiment," Rodriguez says, "and allowed students to focus on the actual interpretation of the data."

But that's jumping to the end of the story. In the beginning, students were asked to use "old-fashioned methods" of mapping an electric field. Rodriguez explains: "Each pair of students was given a piece of gridded conductive paper with an electric dipole drawn on it. They connected the positive end of a 4.5-volt battery to one dot on the paper, and the negative end of the battery to the other dot. At one-centimeter increments, they recorded the strength of the electric potential using a voltmeter. After completing a square of approximately 10 centimeters by 10 centimeters containing the dipole, they were asked to sketch in equipotential lines, and then perpendicular electric field lines."

Next, students repeated the lab using handheld computers and a probe for gathering voltage data. The teacher explains: "They attached the negative end of a voltage sensor to one of the dots of the electric dipole. To the positive end of the sensor, they attached an unfolded paper clip to use as a pointer. To take a voltage point, students would first click on the 'sample' button [on the handheld]. They then clicked on the screen at the matching grid point where they were holding the positive end of the voltage sensor on the grid paper. The grid paper was then changed to a gray scale value that was proportional to the strength of the voltage there." Students continued mapping, gathering data for as many points as they wanted to include.

Unlike paper and pencil record keeping, handheld technology offers students a variety of ways to save their data. For example, the raw numerical data can be saved. Or, a digital "shot" of the handheld screen can be saved to capture the data in a visual format. Students can synchronize the handheld to a desktop computer, then view and print their results.

Rodriguez observed a change in student attitude and interest when the handhelds were introduced to the physics lab. "The arduous task of collecting voltages, recording them on a grid, and later coming back and trying to discern the equipotential lines was removed from the forefront of the experiment. The understanding of what the electric field looked like took over. It was really a successful teaching moment to see the students using the handhelds to remove much of the difficulties in doing the experiment, and focusing on the interpretation of the data," he adds.

Students were also quicker to catch their own mistakes when using the handhelds, Rodriguez adds. "Students caught mistakes as they occurred because of the visual display of the data in real time. In the past, students were so focused on writing down all the data, they lost sight of what it represented." But while students and teacher appreciated the graphical feedback that the handhelds offered, the technology was never the central focus of the activity. "Students first need to understand the concept," he explains, and technology is used in his classroom only to support conceptual understanding.

Students quickly warmed up to the portability of the handhelds. "They could work on lab reports anywhere there was space for a handheld keyboard. This is a tremendous advantage over laptops," Rodriguez adds, "as the short battery life of a laptop makes the proximity to power of prime importance. The handhelds have no such problem, with their long battery life."