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Evaluation Notes: 3 March 2005

Today our plan was to hold a short gallery walk regarding the coaster cars and then allow the students to mess about with balloon cars which we had created. We had a difficult time deciding how to hold the gallery walk discussion. It had been 2 weeks since the students tested their coaster cars, so we feared that they would forget about the important variables of the coaster car design and construction. However, the discussion went relatively well. Most of the students who participated were the students who usually participate and who were also present last week. A couple of variable were mentioned that we, at least, do not think are that important (e.g. aerodynamics and shape / configuration of chassis). We took these opportunities to relate to vehicles from 2 weeks ago, showing that one group that had a funky design in which the chassis hung from the wheels did about as well as everyone else. We also allowed the group that did the best to describe their design to show the class that a standard design could perform very well if assembled with care.

After the discussion we gave each group a base and 3 different balloon engines: normal-length straw, short-straw, and double/normal-length straw. We asked each group to record a prediction about which would perform better and then to record their data when they tested it. We then told the class that after they tested their 3 engines they could try out different designs, as long as they wrote down their prediction and their data when they tested it.

Without exception every group performed only one trial for each of the 3 basic engines. Many groups found that their predictions were incorrect, but we did not push them hard enough to think about why that was. After they were finished with these 3 most groups began trying other designs. We tried to have groups write predictions and data for these other designs but for the most part failed. A couple of groups never completed their “for fun” design and therefore never got a chance to test it. Several groups became unfocused and stopped working on cars altogether. Several students were just roaming the hallway shooting balloons at each other.

I believe this was a far more successful messing about activity than the one we held on week 1. However, I am not sure if we got the students to think critically about the important variables in balloon car design, as their “for fun” designs were just as wacky as their “for fun” coaster car designs were. No groups seemed to be going about things methodically. They would change 50 things in one design and then test it. We almost held a discussion at the end, but ran out of time because some of the groups that were legitimately working wanted to test their final design. I believe a discussion may have helped us focus the students’ attention on the important variables. Perhaps that’s how we should begin next session (2 weeks from today because of their spring break).

Last modified 28 March 2005 at 1:07 pm by Jason Williams