In my post Project Learning – Assessment On The Run I talked about how when you do project based learning you plan the projects to teach specific standards, but students are exposed to and learn a bunch you didnâ€™t plan. I also talked about assessment happening continuously as you observe and listen to your students as they work.
My students have started to build the systems that will support them while they live on Mars (food, communication, oxygen, transportation, recycling and waste, water, recreation and environmental control). As they discuss and design it is interesting and amusing to note errors in thinking and planning. I passed by a group designing a Mars rover and noted that the student making the seats and the person putting the body together werenâ€™t thinking about scale.
I asked the whole group to look at the seats and the body and they really thought they looked good. I had them measure one student in their group sitting in a chair to see how tall they were (about 42 inches). I showed them that if I doubled that height it would be just short of the ceiling in our classroom. â€œIs your Mars rover supposed to be taller than our classroom?â€ I asked. They answered that no it would be about the height of a jeep. I asked them how big the seats they had already built would be compared to a student chair and they answered it would be about the same. Then I asked them how many â€œseats highâ€ was their current rover body and from that they saw how out of proportion they were. By using the seat as a unit of measure they figured out that the rover the one student was making would have been about 35 feet tall (without the added height of the wheels).
Another disconnect was a greenhouse the size of a school gymnasium that was powered by a solar panel the size of the hood of a car (hadnâ€™t considered how much electricity that would make or how much might be required). They did a web search and found a solar panel about 35 feet long and 10 feet wide that said it generated 1000 watts. I explained that would run about 10 one hundred watt bulbs but that a microwave oven might use 750 watts all by itself.
The main difficulty many groups were having was not thinking through the order they should construct things in. What great learning as they would realize they should have painted something before putting it together or just the opposite problem they should have painted after they put something together. I stopped the class at one point and had them note this seeming conundrum.
Learning is messy!