# Day 103: Questions for the #modphys Community

**Posted:**March 18, 2014

**Filed under:**School Days |

**Tags:**problem_solving 11 Comments

I feel like I’ve tried just about everything for problem solving in my college level physics class. This time around it was having the students work on problems yesterday (1-5 from this packet), then today we whiteboarded the problems. In my first period, we both played the mistake game and I had students in a circle. We had multiple groups with the same problem, presenting at the same time, and we compared whiteboards. In 2nd and 3rd hour I had them do more standard whiteboard presentations, as the circle didn’t feel right. In all cases, and in the many ways I’ve tried in the past to present problems on whiteboards, I didn’t feel like the time spent was worth it, particularly compared to simply having students simply work problems with me circulating, giving tips, and occasionally going through parts of the problem on the board.

This is as opposed to whiteboarding conceptual aspects; I see LOTS of benefit in those conversations.

So here’s my questions;

- Do you have a method for whiteboarding or otherwise going through the problem solving process that you have found to be successful?
- Do you think my method of having students work individually/together on problems in class, instead of whiteboarding them, is ok?

Comments are great, since we can have continued discussion, but twitter would be fine too. Thanks in advance for any help you can give me!

I am interested in what others have to say… i feel like I have some of the same ?s

Here’s something I just thought of: in whiteboard groups, half the groups work on problem 1 and write a solution, and the other half on problem 2. Circulate around the room to ensure each group ends up with the correct solution. (For me, when this happens, having the groups explain solutions to the class is wasted time b/c no one really pays attention.) Now have the class swap boards ( 1 2) and ask the groups to explain the solution. This way, students do solve a problem on their own, they also get to explain a worked out solution, AND you didn’t have to take time to write the solution. Ask students how the solution could be improved.

Perhaps the worked-out solution could also be used to learn ADDITIONAL physics. For example, when studying energy conservation, a worked out example on inelastic collisions not only show students a proper solution, but the (surprising?) result that momentum is constant but kinetic energy is not. I know that the “Matter and Interactions” text uses this technique a lot.

Two twists on giving solutions from Eugenia Etkina and Alan Van Heuvelen:

(1) Jeopardy problems: given the solution (with numbers and final answer), create a problem statement

(2) Find the error: given problem statement and (possibly) incorrect solution, find the mistake and fix it.

In both types of problems, the solutions contain two or more multiple representations.

Again, I think the focus is *getting the students to explain.* As modelers, this is at the core of everything we do. This research supports that and gives us a new method (worked solutions) for “getting students to explain.”

“Know how to solve every problem that has been solved”

“What I cannot create, I do not understand”

Both statements were written on Feynman’s blackboard at the time of his death:

I have experienced the same thing.

In fact, I have stopped whiteboarding solutions to practice problems entirely, because it almost always seems like a waste of time. With conceptual stuff (like presenting the results of an experiment) my kids get around to being risky enough to present their findings after a few weeks, but with practice problems, they are still afraid of being wrong and they’ll collaborate with each other until they all agree.

About the only thing that seems useful for this is some version of the mistake game, but you can’t do that every day.

I do the mistake game every day…

I too have experienced classes where presenting whiteboards failed to generate meaningful discussion. What I have slowly come to realize, is that the problems must be chosen carefully such that they are sufficiently challenging such that students have to struggle to solve and then explain their solutions. These problems result in much better class discussion.

I try to do this in two ways. One, we don’t whiteboard every problem; just those that I believe will generate good discussions as students struggle. Two, I’ve started keeping notes of extension questions to ask that lead to a good discussion and new insights or connections. While the initial problem may be relatively straightforward, an unexpected impromptu extension requires the group presenting to verbally share their reasoning as they tackle the extension. This too often results in a good discussion.

This year, I’ve noticed that whiteboarding paradigm labs has resulted in much deeper and richer discussions that practice problems. I believe that too reflects that students are struggling to form meaning more when analyzing the paradigm lab than when solving the practice problems.

Not every problem needs to be whiteboarded. (So long as the kids won’t pitch a fit if you don’t present every problem in class. Which in most (sane) places, they won’t.) The kids usually develop a good feel for what needs to be whiteboarded and what they can skip (because everyone already feels comfortable with it).

But I wouldn’t go entirely to just walking around to the groups. Seeing and thinking through (almost) every problem two or three times seems to be really helpful. (Once by themselves, next by discussion around them, third by thinking through the presentation and mistakes shown.)

Thanks so much everyone. I am heartened in two things; 1, that I don’t have to whiteboard every problem. Secondly, that really the point is to force kids to dialogue and explain, which can be done in many different ways. I think I will continue to lean away from whole group presentations for problem solving in general, but these and other things like whiteboard speed dating are still great ways to make sure kids talk about physics. Thanks again, you made my day.

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I was also having students present every problem. I also was finding it not the best use of time. So, during the energy unit, when they were drawing semi-quantitative bar charts, I went around the room, and when a student asked me a question that couldn’t be answered quickly with another question, I asked, “why not whiteboard it and ask the entire class?” Students went up and presented with a particular question: What should I call the energy the person has before pushing if the person is part of the system? How can you have more Eg if you’re still on the ground higher up on the hill? It was great, and it was much easier than usual for me to get out of the conversation and the students to talk to other students.

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