May 20, 2011

Using Technology with Ninth Graders

Technology can be put to use in ninth grade classes to great positive effect, but the complexity of this technology can sometimes obscure the reality of physical processes.

In February, I visited a private school in the San Francisco, CA, where physics has been taught in ninth grade for a little more than five years. The school is small, about 300 students total, and has taken a progressive stance in educating students not only in the content of the subjects they study, but also in ethics-centered "precepts" that concern each student's identity as a lifelong learner and citizen of a community that is larger than themselves.

The ninth grade physics class is taught by two different teachers through two largely different curriculums. The teachers cover much the same material using very different teaching methods. One teacher, who's method I will focus on here, uses a piece of software to integrate students' notes, homework, lab work, and other class activities into one document. Every student at the school is given an identical laptop, and this laptop is used extensively in the class. During the classes I saw, students used this piece of software to record notes on new concepts, record corrections to a homework assignment done, and access instructions to lab on sound, which itself utilized data collection hardware integrated with software on the students' laptops. (On the day I visited, the other physics teacher did not seem to make extensive use of the students' laptops.)

Students in this teacher's class do not use a textbook, and they do not carry a class notebook. The class is completely "paperless," to the extent that even individual homework assignments are uploaded to a server to be checked for completion by the teacher on the web. Since instructions for the day's lab existed only as an electronic document, most lab groups had at least two computers open: one to follow the lab instructions and one to collect data. This teacher remarked to me that he had not yet been able to explore what he saw as the the true potential of the medium. He envisioned a future for the class that was entirely centered around interactive work, using the notes software to provide structure to this experience. Students would be free to work at their own pace, independent from the class as a whole.

I was impressed by the complexity of the document this tea
cher has written for his students. This was, in effect, a vision of a textbook for the digital age: seamlessly integrated with computer simulations or data-collection software; unified to include content from both teachers and students, but segregated enough to identify one from the other; easily updated and revised to reflect modifications in the curriculum or mistakes found in the document.

However, when taking notes on a laptop in physics class, students can run into great difficulties in formatting. Notes in a physics class often involve heavy use of diagrams and equations, and representing these in a standard text editor ca
n be difficult or confusing. This teacher had tried to address these issues by including into his document pieces of particularly crucial diagrams. One feature of the program made it possible to embed regions designed especially for free-hand drawing. Though this feature made it easier for students to draw arrows and other simple shapes, the whole process seemed quite awkward. Perhaps, with the inevitable arrival of touch-screen tablet PCs, this limitation of electronic notetaking will be eliminated.

One common downside of an increased emphasis on technology in a physics classroom is that the technology can obscure the physics. During this lab on sound,
for example, students were using a computer microphone to automatically draw graphs of pressure versus time of the air around a vibrating tuning fork. At one point, students were instructed to change a time value in the settings for the program to allow them to see how the amplitude of the sound wave decreased as time passed. Depending on how students interpreted the instructions, they ended up with graphs that looked like one or the other of the following two graphs, both displayed over a time period of 4 seconds:

Slow Sampling Rate:
Fast Sampling Rate:
Though these graphs both show correct measurements of the same phenomenon, the graph on top was made using a "sample rate" of 0.03 seconds per sample, much too slow to represent the rapidly changing pressure of a sound wave. This misleading graph would lead one to believe that the tuning fork the made the sound was vibrating an an unreasonable 6 Hz. The graph on the bottom was made with a sample rate of 0.0005 seconds per sample, and correctly shows the uncountably high number of oscillations that take place over four full seconds.

As they took data, students looked around the room and compared their graphs to the graphs of the other students. Students whose graphs looked like the latter graph shown invariably concluded that they had made a mistake, since the graph didn't look like the "sine-shaped" sound wave graphs they'd previously seen. Because of confusion stemming from a simple error in setting up the software, student misconceptions about the connection between sound waves and the "sine-shaped" representations of these waves were unwittingly reinforced.

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