On-line: The School of
A Hopkins professor has built a "virtual laboratory" on the
World Wide Web to give engineering students a taste of the
challenges they may someday face on the job. With a few clicks of
a mouse, students drill for a hidden supply of oil, program a
robotic arm and design digital logic circuits.
Putting such experiments on the Internet introduces students to engineering without the high costs, time constraints and space limitations imposed by a real-world laboratory, says Michael Karweit, inventor of the on-line lab.
"One of the difficulties with a laboratory course is that it's expensive," says Karweit, a research professor in the Department of Chemical Engineering. A typical undergraduate electrical engineering lab, for example, might need 30 oscilloscopes, each costing about $5,000. With these tools, only 30 students could conduct experiments at any one time.
"Now, suppose you could simulate what you're doing with 'virtual' equipment," Karweit says, "something that exists only on a computer screen but allows the user to affect what's going on. You might start with a program that gives you the image of an oscilloscope. On the screen you could hook up wires to the instrument. With a mouse you could move its knobs. You could simulate exactly what a real oscilloscope would do if you had one in front of you.
"You might argue that students are not going to get the full experience when they use virtual equipment. But suppose you get 80 percent of the effect, yet the cost is only 10 percent, compared to a real laboratory. It might be worth it. And any student with a computer and access to the Web would be able to use the virtual equipment."
Karweit's concept won him a "best paper" award at a recent meeting of the Association for the Advancement of Computing in Education. In the paper, Karweit said virtual labs may be particularly valuable in part-time engineering programs and those at community colleges, where space and funding for labs may be scarce.
The Hopkins professor also sees the on-line lab experiments as a way to let freshmen sample the type of real-life puzzles that working engineers confront. This early exposure is important, Karweit says, because most engineering students spend their first two years at college mastering chemistry, physics and mathematics. By the time they take their first engineering courses, they are often in their junior year--a rather late date to find out whether they indeed possess the interest and aptitude for this field.
To give freshmen a clearer idea of what the profession involves, Karweit used the Java programming language to create interactive lab problems on a Hopkins Web site. "I wanted these experiments to concentrate on real-life problems, as opposed to textbook problems where you can thumb through the chapter and find a formula to solve them," he explains. "I wanted to present problems that did not necessarily have a single solution. In some cases, you are forced to approximate a solution. That's what engineering is about: finding a way to solve problems while working under many types of restrictions--political, financial and environmental ones, for instance."
In the oil-drilling experiment, students must determine the shape of an underground layer of oil-bearing shale and do so at the lowest cost. With each mouse click, the student drills a test well and is "charged" $500. For each well, the experiment indicates the depth at which the oil-bearing layer was found at that location. When a student has finally figured out the layer's shape, he or she can "capture" the distribution of these wells and the total cost from the screen for inclusion in a laboratory report.
At Hopkins, Karweit has already used the virtual lab in an introductory engineering class and in a summer course for gifted high school students. "Most students liked it and got a kick out of it,'' Karweit says. "But a few were miffed because they had no particular recipe to follow to obtain a solution. They had to figure it out for themselves."
Although on-line experiments can enhance an engineer's education, Karweit cautions that they do not eliminate the need for lab time in the real world. "In spite of the fact that they can offer highly interactive experiments, virtual laboratories cannot duplicate the experiences obtained in handling real apparatus," he says. "But when laboratories focus on design or problem solving, and when lessons are not dependent on physical equipment, the educational differences between real and simulated narrow to the point where virtual experiments become very viable options."
The free virtual laboratory Web site is located at: http://www.jhu.edu:80/~virtlab/virtlab.html.
Karweit's project was supported by a grant from the university's subcommittee on electronic and distance education.
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