The following is the discussion guide I wrote myself for 9th grade physics students, 2/3 of the way through the year, on the first day of our electrostatics unit.
Until now, we’ve modeled mostly visible phenomena. This term, we switch to more invisible stuff. Get out a sheet of paper and answer these questions solo before we discuss them.
- What invisible phenomena have you already learned to model? Here’s a list of all the models you’ve learned. Sort them into visible/invisible buckets:
- Constant Velocity Motion
- Balanced Forces
- Constant Acceleration Motion
- Unbalanced Forces
- Projectile Motion
- Energy
Be sure to allow room for students to sort differently. Some will put forces in the visible bucket, for instance. Ask them to explain their reasoning. Find one that we can all agree is modeling an invisible (or partly invisible) phenomenon. We also had a discussion here about the importance of sharing your reasoning after y’all called peers’ different sorting valid.
- How did we do that? That is, what do we already have in our skills toolbox to model what we cannot see? Think back to those invisible phenomena to name specific examples.
Be sure to discuss 1) linking the invisible to the visible phenomena (motion/forces for ex.), 2) simplification, 3) metaphor.
Given that we’re going into more “invisible phenomena” territory this term, you’re going to add skills to that metaphorical toolbox.
- Why is a multi-representational model important? That is, why do you think it’s useful to use pictures, words, equations, and graphs to model a phenomenon?
Be sure to hit on “no one representation tells the whole story.” While they may want to talk about some reps being better entry points or making more sense to them, push students beyond a discussion of “learning styles.”
- The toolbox of skills you’re building goes beyond just creating models to represent phenomena. Let’s step back from modeling skills for a bit and look at all the skills this course is meant to teach. I’d argue you’re learning these skills in multiple other classes. Where are they turning up? Which are surprising?
| Practice.1 | Asking Questions and Defining Problems |
| Practice.2 | Developing and Using Models |
| Practice.3 | Planning and Carrying Out Investigations |
| Practice.4 | Analyzing and Interpreting Data |
| Practice.5 | Using Mathematics and Computational Thinking |
| Practice.6 | Constructing Explanations and Designing Solutions |
| Practice.7 | Engaging in Argument from Evidence |
| Practice.8 | Obtaining, Evaluating, and Communicating Information |
We took a break then came back to explain why this balloon is hanging from the textbook.
Students talked about interactions, drew force diagrams, and came to the conclusion that there’s an interaction they don’t yet understand happening between the balloon and the Giancoli text.
For those with no prior experience with electric charge, they were able to describe that the fur did something to the balloon to make it “sticky” (and that I could remove that something by brushing my hand across the balloon a few times).
A note about discussion notes: I’m not the best at Socratic Dialog in a whole class setting. I struggle to involve more than just a few voices, to uncover real ideas, and to feel like the result was worth the time invested. This discussion felt different. Why? Maybe it’s because this was the first day of a new term — students were feeling refreshed and were ready to start anew. Maybe because I came with a good set of questions — I know that good Socratic Dialog require a good progression. Or maybe it was because of the…checks lunar situation…waning crescent. Either way, I’m encouraged and will continue pressing on.
Megan Hayes-Golding 