First Teaching Experience!

I volunteered for IBM's "eWeek", an engineering outreach for middle school students with an activity called "Alternative Energy -- Breath of Fresh Air and Catching Rays". The goal was to show students that math and science are fun and to consider engineering as a possible career path. The specific goal of this particular activity was to demonstrate electromagnetic induction and photovoltaic effect as two methods of producing electricity, and implications in alternative energy.

We did an introduction discussing electricity and how it is used and generated, the difference between voltage and current, and the differences between renewable and non-renewable energy sources, and then moved on to the hands-on activities. One was a simple generator involving a magnet and a coil in a plastic tube that could be shaken similarly to a shake-flashlight, to see how much voltage could be generated. Next was wind power using small toy motors as generators with propellers attached, and using an electric fan to make the wind. Then a solar experiment with incandescent bulbs and small solar panels to test the effect of distance and angle and any other factors the students could think of on voltage output. Lastly, a race between two toy solar cars, one powered by an incandescent bulb and one by a fluorescent bulb. Both appeared to have the same intensity, but only the incandescent was able to power the car and we discussed why that is.

I didn't prepare as well as I would have liked because of other commitments, but felt ok about this because I had an experienced partner for the first session and so could mostly observe during the first session and then do the second session "for real". I think my biggest weakness was knowing when to make the students come up with answers on their own and when to simply tell them the answer. I spent too much time trying to get them to come up with answers that they probably had no idea about. Overall I came away having great respect for teachers who do this all the time!

Thoughts for next time:

In the first class we didn't do a very good job of explaining how motors and generators are the same but just used differently, but in the second class we did and they were visibly fascinated by that idea. If I do this again I'd like to allow time to show that the big fans can make electricity too. In my own experiment beforehand I got a peak of 100mV from one fan by blowing on it with the other fan. This can be set up and demonstrated in about 30 seconds.

I had been hoping to bring a disassembled motor into class to show them how it has magnets and coils just like the homemade shaker generators, but I didn't have time. After it was all over, I noticed that there was one disassembled toy motor in the multimeter case. We should pass that around next time.

Jon, next time don't tell the kids that you don't use math at work! If you feel an ethical dilemma start using math at work somehow. Maybe derive the equation of a circle using calculus or something during your lunch break. (Joke light)

We talked about electrons moving through wire. Next time I might mention the difference between conductors and insulators briefly.

We wrote "Electromagnetic Induction" on the board. Under that perhaps we should write "Photovoltaic Effect" which is the solar equivalent.

How about a take home sheet on how to make an electromagnet at home using a battery, a nail, and some wire just for fun? I'd write one!

The kids seemed more open to receiving a lecture than I expected. There isn't much time for this with a total time of about 50 minutes, but good to keep in mind. I don't think we should worry too much about being sure they completely understand all the theory although we should do our best. The goal is more to make them curious than to truly teach them, I think. The thing to be strict about is making sure they write down their predictions before the experiment, and observations after, and their ideas for improvement.