For the last two weeks, I got to do my first lab in the seventh grade science classes. Last week I went in on Wednesday and Thursday for Mrs. Karalash's classes, and this week I was in Mrs. Buckwalter's classes on Tuesday and Thursday (Wednesday was a field trip day). The lab was about designing and building earthquake-proof buildings, which is an activity that has many different versions all over the internet. None of these versions seemed to fit our purpose well, so I created my own version of a two-day lab, where Day 1 was about brainstorming and designing and Day 2 was about building and testing.
I started Day 1 with a three-part powerpoint-based discussion that was only supposed to take up 15-20 minutes before leaving the students with 25-30 minutes for brainstorming, designing, and selection of a final design. The first part of the discussion was about engineering design, which began as 12 slides in Mrs. Karalash's first class and ended as 3 slides in Mrs. Buckwalter's classes. The point of this was to introduce the students to the engineering design process, using a lot of the slides that I presented to some high-schoolers a few weeks ago on campus. This seemed to be way too much, as the students' attention waned very quickly (prompting the gradual removal of 75% of the slides). The second part of the discussion was on earthquakes in general, and I showed a news clip video that talked about a company that retrofits buildings for earthquake-resistance. I followed this up by discussing some ways (from their textbooks) that buildings can be designed to minimize earthquake damage. We also used this time to answer the pre-lab questions that were on their worksheets: What happens during an earthquake? Can we predict where and when they will occur? What dangers do earthquakes pose to people? How can we as designers and engineers prevent some of these dangers? In Mrs. Karalash's class, we answered all of these questions together as a class, and we basically told the students exactly what to write on their worksheets (though some still neglected it); in Mrs. Buckwalter's class, we let the students come up with their own answers (and gave them some time to do so).
The third and final part of the powerpoint introduced the design activity - to redesign the Port-au-Prince (Haiti's capital) City Hall, which was destroyed during the earthquake back in January. In Mrs. Karalash's classes, I explained that the student teams were design firms competing for the contract against the other "firms" in the class, and we listed 4 or 5 design criteria that they will be evaluated on (earthquake-resistance, appearance, functionality, cost/environmental friendliness). This seemed to go over their heads, so in Mrs. Buckwalter's classes I simplified it and just said that their job was to design the new City Hall. From here, I explained that their assignment for the rest of the class was to brainstorm and draw at least 5 different building ideas, and then as a team to agree on one final design to start building the following day. Depending on the class, the students typically had between 10 to 20 minutes for this part, which didn't seem like enough time. We also had to continually remind the students of what they were tasked to do, as they seemed to have a lot of listening problems. The goal was for them to have detailed drawings of what they planned to build so that they could come in the next day and immediately start building. Unfortunately, this didn't happen for the majority of the teams.
Day 2 was all about building and testing, which had varying degrees of success in each class. Before we gave the students materials, we made them finalize their designs on paper ("measure twice, cut once"), and depending on when they did that, they had 10-25 minutes for building. After they finished building, we weighed, measured, presented, and tested the buildings. This went very differently in Mrs. Karalash's classroom than in Mrs. Buckwalter's classes, partly because of the classes themselves and partly because we had a chance to learn from the earlier classes to improve the later class experiences. In Mrs. Karalash's classes, we typically needed 15 minutes or so for the students to finalize their designs before they could get the materials, and then we gave the students 10-20 minutes to build. The students didn't know how to use the scales, so we set up a "height-measuring station" where Mrs. Karalash used a meter-stick to see how high the buildings were. Then they came over to the "weight-measuring station" where I weighed them using the balance scale. After that, the students had a chance to present (and many of them got very shy or had nothing to say) and then we shook it. Unfortunately, about 4 buildings into the first class, the shaker fell apart. There were several problems with it, and I tried to fix it before realizing that I didn't have the materials, which frustrated me through the end of the hour. For the rest of the day, I settled on just holding the motor down by hand and adjusting the rotating arm between each test. Because of this three-stage process of testing, we were always rushing to finish on time, and we never had time for the reflection questions, which was unfortunate. In Mrs. Buckwalater's classes, we let the students weigh and measure their own buildings during the "build" phase. This meant that when we started testing, all we had to do was present (and the students had fewer problems speaking in front of the class) and test it with the shaker. It helped that the shaker had fewer problems, though I still had to find something heavy to weigh down the top of the shaker table and adjust the rotating arm between tests. Still, we were able to get through this stage much more quickly, and we actually had time to let the students answer the reflection questions and turn in their lab worksheets.
There are some more major differences that I noticed between these 7th grade classes and my high school algebra and geometry classes that I worked with for the previous two and a half years. One of them is that the teachers tend to step up and take charge a lot more than in the high school. I was expecting to lead the entire two days by myself, but in both classes the teachers tended to take over and help lead the activity. This was somewhat a relief to me, because I'm not sure if I'd be able to settle down some of these classes by myself. In the high school (at least with the teachers I worked with), the teachers were all too happy to hand over the floor to me, and often took the opportunity to catch up on work, leaving me relatively alone to deal with any distractions and keep the students' attention. The other thing is just the maturity levels of the students, which is much lower than what I saw in my high-school students that were typically 2 years older.
