Senior Jim Nolen from Houston, Tex., was named recently by Computing in Science and Engineering magazine as one of three winners in its 1999 software contest. Under the leadership of physics professor Wolfgang Christian, Davidson has brought home prizes in eight of the contest's ten years, including the last six years straight. No other college or university anywhere has done as well in the international competition.
Nolen's software models the behavior of gasses inside containers, and is useful in understanding the relationship between pressure, volume, and temperature. He developed it during spring semester 1999 as an independent study project under Christian's guidance. Christian himself has won several prizes in the contest through the years, include the only "Grand Prize" ever issued.
Nolen explained how his program, and many others developed at Davidson under Christian's leadership, make it easier for students to learn physics. "You can't see a lot of the things you study in physics," he said. "By developing interactive software that simulates molecular and atomic principles, users can get a much better conceptual understanding of what's really happening."
Interactivity is Key
Nolen's program becomes part of Christian's ongoing work to integrate interactive, customizable exercises accessed through the World Wide Web into physics instruction. Christian and two collaborators, Dr. Gregor Novak (Indiana University) and Dr. Evelyn Patterson (United States Air Force Academy), received a $304,000 grant from the National Science Foundation two years ago for development of this instructional concept into a complete physics curriculum.
Christian's approach gives students the information necessary to solve physics problems in an interactive simulation, rather than in a written text question. Students solve the problem through observation of motion, application of appropriate physics concepts, and measurements leading to mathematical calculations.
A Different Approach
Such an approach is remarkably different than typical novice strategies where students attempt to mathematically analyze a problem before qualitatively describing it. Teachers often call this approach "plug-and-chug" because it is characterized by the lack of conceptual thought during the problem solving process. Christian believes that requiring students to consider the problem qualitatively, as is done in multimedia-focused problems, has a positive influence on their problem-solving skills and conceptual understanding.
Christian and his students have so far developed about 25 of these interactive exercises, which he calls "Physlets," (c) which are all accessible via the World Wide Web. The exercises are written as Java computer language "applets" so that they can be accessed via all popular computer operating systems. They are free for non-commercial use.
Christian noted that Physlets allow instructors to create situations that can't be replicated with real life materials. The "Optics" Physlet, for example, can demonstrate many different types of optical systems, from astronomical telescopes to cameras to microscopes. Students can click and drag to move the lens around, try different light sources, and actually grab the lens edge to make it thinner or thicker to change its focal length. Christian said, "You can't do that in real life, so that's why we call these 'media focused' problems rather than multimedia - you have to interact with the medium to understand it."
Changing the Approach
The magazine contest judges agreed that the Davidson entries have achieved something that is difficult to do in writing pedagogical software- "engaging students in activities that will teach them something tangible... Students must do more than click and watch, they must be engaged in a process that regularly stimulates cerebral activity... Ideally, the program should approximate an authentic dialogue between a learner and an expert."
Media-focused instruction takes advantage of the World Wide Web in ways that Christian believes are too rarely used. He explained, "The web is often used to publish megabytes of information that could just as well have been printed on a page. But that's not likely to have an impact on learning. You're not changing the pedagogy or approach to what the student does. We're trying to change the basic approach."
In addition to the interactive Physlet programs on the Web, Christian relies heavily on a "Just In Time Teaching," (JiTT) technique developed in conjunction with Drs. Novak and Patterson. For homework assignments, students work Physlet problems on the web that correspond to class discussions, or extend just beyond what the class has been studying. Students stay on-time and on-task by using the Web to create a feedback loop. By reviewing their assignments just before the next class, Christian gets a good snapshot of the class's understanding of the subject matter, and can tailor the next class lesson with that in mind.
During the three-year duration of the NSF grant, Christian is developing an entire undergraduate Web-based physics curriculum that includes Physlets and JiTT. The grant also funds production of a CD of Physlet problems and concept problems for JiTT, and funds for Christian's regular presentations about Web physics at professional meetings of the American Association of Physics Teachers.
Learning the Basics Early
Nolen, like other Davidson student winners before him, traced his initial interest in web physics to Christian's "Computational Physics" course that he took as a sophomore. "I had never done any programming before that, but I enjoyed the course very much," Nolen said.
Christian said most schools teach computational physics as an upper level course and as a specific skill, rather than teaching it early and urging students to apply it throughout the curriculum. Nolen was one of the students Christian regularly recruits from that course to help him create Physlets during their junior and senior years as independent study projects. Nolen worked on it independently, with Christian helping test results and brainstorm about exercises and function.
Christian believes that computational physics represents a major
change in the way the discipline is taught. He said, "The technology and the way
we do this puts students on an equal footing with the faculty. They soak up the
technique and technology as fast as faculty can, so our projects are much more a
cooperative venture than the traditional relationship. I learn from them as often
as they learn from me."