Physics 11 – We used most of the class to look a how friction could be modeled on the microscopic level, and the factors that affect friction. The first class brainstormed possible factors that affect friction and then broke into groups to investigate a factor. However, a few groups had a difficult time clearly identify friction force as the dependent variable, and a variable that they could directly measure.
I had the second class work through a more structured approach to designing their experiments, where the dependent variable was more explicitly stated and recognized as being something that could be measured. We used the Smarter Science framework to assist with this. We didn’t have time to carry out the experiments, so that will be done the next day.
Science 9 – Today in science 9 the students extracted DNA from strawberries. The lab is fairly straight forward and is well known in education. With not too much prep, the students are actually extracting DNA – every time I think about this, it blows my mind! Most of the students find this pretty interesting too.
Of course, this lab is one of those black box type investigations. I have thought about following up the quiz with an experimental design lab. Some type of investigation that determines how to maximize the quantity of DNA extracted. Perhaps I will go over an experimental design next class, using the Smarter Science framework.
One of my blocks had several boys that really struggle to stay focused. Some of them are super interested in this topic and what the lab is about, but have absolutely no desire or compulsion to write something down on paper. It’s a puzzling thing for me to figure out – I feel like I’m doing all of the things that need to be in place for an engaging environment, but several kids just aren’t in the right head space.
Science 9 – Like my grade 8 classes, I decided to do a Smarter Science activity with the grade 9’s using the dissolving starch packing peanut. I had noticed that in their previous lab, the students had a difficult time carefully thinking through their experiment even though most of it was laid out for them. It seemed as so they could use more scaffolding in creating experimental procedures.
The grade 9 classes were able to work through this experiment fairly quickly. As well, their inquiry questions were more focused. Most importantly, many groups recognized that they were missing two key parts for a successful experiment. First, some groups discovered that they needed to properly calibrate their timing. In other words, they needed a way to control when the timer should be stopped. When is it an appropriate time to say that all the dissolving is finished? The packing peanuts do not fully dissolve. The other key piece that was missing was their ability to control the stirring. Many groups independently worked out a stirring rate, but others were not clear on the issue of pushing the peanut into the water (the peanuts float).
I’m hoping that the lab reports are finished promptly and are of decent enough quality.
Science 8. Today we worked through an experiment using the Smarter Science framework. I could see its usefulness, as there were several places where students were tripping up in the process. In previous classes we talked through the experiment while I wrote things down on my tablet. Today’s class I tried using the post-it notes as shown in the photo above. I think that for grade 8’s, the overhead projector with both me and students writing at the same time was better. Using post-it notes left the kids doing nothing for a bit… They would just be watching me move the notes. It caused them to be too distracted.
What was really interesting to me was that a few students ended up with test procedures that were trying to test two variables at once. I’m looking forward to doing this again soon.
Today in Science 8 we debriefed our starch packing peanut experiments. I was actually quite surprised at how quickly the students picked up on the errors of our experiments. Students identified that:
- different peanuts had different masses
- water temperatures were not controlled well enough
- Stir rates were not controlled well enough
- How the floating peanut was dunked was not controlled
Furthermore, students were able to come up with solutions to the problems. Generally they suggested doing more demonstrations, having someone specialize in a particular step or procedure, and the use of pictures and videos for setting standards. Many of these things are tools that we use for QC in engineering.
As with all group discussions, just because one student offered up a good answer doesn’t mean that all students had the same idea. However, I was very careful to elicit information from almost all students. Usually there will be a few students that claim they don’t have anything to say. For these kids, I give them ample pause time before letting them off the hook; however, I always tell them to keep thinking because I will come back to them. Often these kids are eager with their hands in the air before I get a chance to ask them a second time!
Today we worked on observations, by recording details of apples and then studying how a starch packing peanut dissolves in water. This led to our next discussion about scientific methods: asking questions, and coming up with testable ideas. What follows is a list of questions the students had about packing peanuts. With my help, they then decided on which questions were testable in our classroom (highlighted in green).
Of course, that we’re not going to test #1 is a major disappointment! Next day’s plan is for the students to split up and devise an experimental plan to test one question (per group). With these activities, we will go over experimental design and controls in an interesting and authentic way.