I want to do a better job of teaching my students how to practice physics. When I tell them which skills need work (see the SBG tag for more details), I want them to have some ideas about what it looks like to practice those skills. We say practice, not study: practice definitely means there’s a pencil in your hand (no pen in my physics class because you’re required to make mistakes) and a new piece of paper in front of you.
Time to grow some myelin
Here are some ideas that I’ve given students in the past. I’d like to keep adding active, quick, obvious (that is, easy for kids to see what to do and get started on them right away, even though the work itself isn’t easy) ideas to this list. Cover up your work and try the problem again without seeing what you did before is a clear one (one that some, but not all, of my students think to try anyway). After you’ve done that, you can:
- Work the same problem again, but this time add the answer to the given information and take away something that was originally told to you. That way the problem is new, you won’t be just using the same procedure with different numbers, but (and here’s the really great part of this strategy) you’ll immediately know if you did it wrong because you already know the new “answer” to the question.
- Go back to old units. Rework an old problem using newer models. Do they apply? Do they work as well? Better? (Example: go back to the momentum unit and see what happens when you analyze the collisions and explosions using conservation of energy. Go back to the unbalanced forces unit and use energy and/or momentum to analyze the problems again.) This strategy works especially well for the goal-less problems in the old units. Look at what you didn’t know you would be able to do, back in the day! If you have too many unknowns, try making up one more piece of information at a time.
- Turn the problem into a goal-less problem. Add more information, one piece at a time, if you have too many unknowns. Goal-less problems build in so much extra practice, it’s crazy. Now that we work these problems often, my students have probably drawn hundreds more graphs than they would have drawn just to solve the problems. They also seem to be a lot better at drawing and using those graphs when the time comes, too.
- Play with the model until you break it. Example: how many different ways can you define your system while you are solving this energy problem?Most students start with the pig and earth (and, if it is early in the unit, also the hill) inside the system. But what happens if you take the earth outside of the system? What if you put the hill outside the system? It is delightful when both of those work out to give you the same answer. Now, what if you take the pig out of the system? They try to draw the LOL diagram and poof, the model is broken.
Can you do this by watching a video?
I’ve reread Mark’s post on deliberate practice, and something about it keeps bothering me*. His descriptions of practice in swimming almost all involve the swimmer in the pool, actively working. But the descriptions of practice in physics (he describes how his students use the videos he occasionally makes for them) don’t strike me as very analogous. The physics students are not as actively engaged in doing physics as the swimmers are in swimming. If anything, they seem a confirmation of the inefficiency involved in learning by watching.
It seems to take many watching to begin getting value out of the process. Once that value is achieved (aha, now I get how this problem works, how to add vectors, etc), it is hard to imagine a student watching that same video many additional times (as opposed to something from the list above, which they could keep applying to the same or different problems). It is easier for a student to watch a video about a problem or a skill and feel that they “get” it without actually understanding it than it is for them to get the same false positive from playing with a problem.
When it comes down to it, I just don’t see (yet?) a way for my students to really practice physics using videos, even ones that I make for them. When it comes to growing myelin, doing is much more efficient than watching (as I understand it). Maybe I’m just being stubborn. I’ll keep thinking about it. For now, though, I’m leaving it off my list.* FYI: Mark and I share an office, which is why I feel so comfortable picking on him. I’m sure he will return the favor!