September 2001 — Features
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The Viability of Distance Education Science Laboratories
Students began the experiment with an instructor-prepared spreadsheet that collected and graphed the raw digital sound data as the noise was created. The spreadsheet included the Fourier analysis and graphics tools necessary to analyze the frequency spectrum of the sound data. Students directly controlled the parameters by changing appropriate cells of the spreadsheet. The full lab instructions and spreadsheet were part of a Web page, and could be used from any computer with the spreadsheet application and an Internet connection.This lab was conducted in a traditional setting, during a scheduled time with the instructor, computer, apparatus, musical sound sources and students at the same location. However, in addition to sounds made by students locally, a sound source located in another room was included for students to analyze. By changing a cell in the spreadsheet to the distant device address, students collected data from the unknown sound source. Determining the frequency of that source required students to experiment with the measurement instrument sample rate and the number of data points collected. As part of the laboratory report, students explained the accuracy and error inherent in the measurements, requiring an understanding of instrument limitations, experimental design and the spreadsheet tools used to analyze the data. Unanticipated benefits from using the spreadsheet approach were the very low development effort for the instructor and the opportunity for students to follow an investigative approach not anticipated by the instructor.
In another experiment, computer science students in a networking class used a Web browser that ran a Java-applet as an oscilloscope analyzing a digital signal. This started as a traditional laboratory with one computer running an oscilloscope program, another generating the digital signal and an analog-to-digital converter instrument measuring the signal. Though there was no scheduled laboratory time, stu-dents often had to queue for access to the single-equipment setup. The replacement distance laboratory was developed mainly for presenting a networked application example, not directly to benefit waiting students. However, because the oscilloscope was part of the laboratory Web page, all instructions, tools and equipment were readily accessible to students over the Internet, making the single setup of equipment sufficient. As another unintended benefit, because any computer could be the oscilloscope and students preferred to do the experiment from home, the setup back in the lab needed only one computer with the analog-to-digital converter instrument.
Our third example presents a potentially enormous benefit of distance laboratories: the possibilities for new science education models to ignore time and place. The setup consisted of three antennas designed to receive extremely low-frequency electromagnetic signals. They were buried at the edge of our campus, making direct student and instructor access physically difficult. In this case, students could not change instrument parameters, but could only collect and analyze the signal data so that an observation by one student using the same instrument did not interact with another’s observation. This model would be generally useful where many students monitored equipment that is otherwise inaccessible, such as remote weather stations.
