Physics 11 – Today’s lesson is typically one of my favorites for the year. Students brainstorm factors that affect friction and then they test out their ideas. In the past I let the students have all the say in their work. However, last year I noticed that several groups were doing pretty crazy stuff – mostly they weren’t measuring forces at all. In other words, they weren’t clear on what was the dependent variable in their experiment.
So this year I gave them more structure:
This helped with the experimental design but there was an unintended consequence. The students gave up their agency. The day became more about me. In general the students were asking “what do I do next?” and saying “I don’t know what to do.”
I’m not sure what I will do next year. If I had more time, I would run through the above sheet on a different experiment, and then let them figure it out for the friction inquiry.
Here is a link to the above Friction Experiment document.
Science 8 – Students had 20 minutes today to be tested on their ability to come up with an experiment using the Smarter Science framework. The scenario I presented to them was: I pulled a wooden block along a desk surface with a spring gauge. Above is the rubric I will use for grading their work.
Science 8 – Following from last day, a few kids designed an experiment where they wondered what would happen to the pouring rate if the temperature was changed. That’s fantastic, because there is another lab in the textbook that covers this.
Today’s lab focus is data collection and graphing. They’ve already worked on experimental design and the procedure for this test isn’t very obvious. The graphing is a bit difficult though, because after the temperature of corn syrup reaches 55C, the data gets unreliable. They are measuring the time it takes for a steel BB to drop through 200 mL of heated corn syrup, and after 55 C the viscosity is so low that the time is less than 1 s. This makes timing very unreliable and inaccurate.
I looked over the Smarter Science sheets that the kids made and it was pretty good. The most difficult part of this process seems to be picking the dependent variable. What can the observe or measure that will determine if there is an effect or not? Many kids could not identify this, or also included independent variables.
Science 8 – In science 8 we continue to use the Smarter Science framework for developing experimental design. For today’s class, I started out by pouring some corn syrup into a beaker of water. The idea was to stimulate kid’s observations and wonderment about viscosity. By having a beaker with water in it, the students are reminded that corn syrup and water are probably different.
I had the students fill out a level 2 Smarter Science experimental sheet, which I plan to take home and give feedback.
For today though, I took the idea that several kids had which was to test pouring rate. This is close to a lab that is in the science 8 textbook. So while the kids followed a set experimental procedure, I think many will have come up with the overall design of the experiment by themselves with correct dependent variable, independent variable, and control variables.
Science 9 – This is a result from one group’s experiment with yeast budding. Their experimental variable was water pH, and it looks like they may have made a mistake. This turns out to be excellent for everyone because it will give the class a chance to apply reasoning to an experimental results.
E: pH 3
F: pH 5
G: pH 7
H: pH 11
If maximum gas was at pH 7, then clearly the pH 3 solution should have less gas than the pH 5. It’s hard to tell from the picture but balloon E was the 2nd fullest. A few students were able to apply CER (Claim, Evidence, Reasoning) to find this mistake.
Science 9 – In an effort to unravel what happens with the paperclips, I had the students walk through an experiment which would hopefully isolate one variable to test. The Independent Variable turned out to be heating time, keeping everything else the same. This time around the students were careful to pay attention to flame height, where in the flame the paperclip was placed, etc. Unfortunately the results were just as inconclusive as before.
Science 8 – Today the science 8 classes started work on experimental design. I totally love the Smarter Science approach to inquiry and experimental design.
At some point I mention how we really don’t need a hypothesis for an experiment, what we really need is a question. There were a couple of students that were visibly pleased when I mentioned this, I guess they were also confused as to why we have to guess an outcome when there is no benefit in doing so.