Show me the physics, not just the math

Have you heard about Global Physics Department? If not, allow me to tell you about it, because it’s one of the best professional development activities I’ve found. Global Physics Department (GPD) is a group of physics educators that meet in an online conference almost every Wednesday night at 8:30pm Central. (Here’s a link to the Posterous site that is a gateway for connecting to it.) High school and college physics teachers meet for about an hour to discuss matters related to teaching. Sometimes guest speakers discuss what they’re doing and attendees ask questions via chat. Other times, teachers submit videos of their teaching and get feedback from the group. Andy Rundquist from Hamline University is our gracious host and moderator.

I’m so glad to have discovered it this school year. I’ve learned a lot from the sessions I’ve been able to virtually attend. Here’s a case in point. Last semester, Andy invited participants to submit clips of teaching for feedback from members. Since a student of mine had some absences due to illness and I’d worked with my school’s media resources department to record a few classes, I had some recorded material ready to go.

I submitted the clips, which I gathered from a session from my intro course that happened to be on the ideal gas law. Fellow group members viewed them and then during one GPD meeting I received feedback from the group for about 15 minutes. I used a microphone to be able to respond to questions and comments that came either verbally from the moderator and a couple of other users, or from the users as a whole from chat within our online meeting system.

I was blown away by the feedback I got and the level of impact it’s made to my teaching. First, let’s consider what kind of usual feedback a professor like me gets. In my previous position, the only time any fellow faculty member viewed my courses was when a colleague of mine and I took the initiative to start a voluntary peer observation program. At my current institution, I had one observation my first semester and will presumably get another sometime this semester in time for me to complete a formal second-year review. But those are and will be fairly perfunctory, more of a way to check for satisfactory teaching performance rather than being geared towards real improvement. Of course, along the way I’ve gotten the standard end-of-semester formal evaluations from students and done my own informal mid-term evaluations. All of these have been somewhat helpful for avoiding terrible classroom habits but not terribly illuminating.

When my teaching session was observed via GPD by my peers at other institutions, a major piece of feedback came out: the need for me to emphasize physical meaning behind proportional thinking in equations. That statement doesn’t seem to really explain it very well. Here’s some context: in the teaching clip that was viewed, we looked at the ideal gas law equation and did some clicker questions that asked students to determine by what factor the temperature would increase if the pressure increased. The students did well, most of them getting the answer “right” – but I put “right” in quotation marks because there are different levels of right. GPD members suggested that maybe the students were primarily thinking through the math and not through the physics that causes the change in temperature.

This had a remarkable effect on how I think about teaching physics now. I shudder to think how often I have rewarded students for being able to do math (important in and of itself, of course) but not really tested if they were doing the physics – thinking through how the gas particles were changing with the increase in pressure, in this case.

Very soon I saw benefits from this feedback, which came at the end of last semester. The first week of classes this semester, I gave students this clicker question regarding some topics we had been covering on light:

Almost all the students got the answer right (it’s #4, by the way). In the past I would have told myself, “okay, they’re getting it, let’s move on.” But this time I pulled out one of my new favorite classroom tools, mini whiteboards, and asked them, “now, draw a figure of what’s going on and prove that that’s the right answer. Can you show via a drawing the real physics of the scenario?” And it was clear that the students had relied on the math to get the right clicker answer.

We ran out of time for that class period, but that was really a good thing because it left the students wondering about how to really get the right answer through physics. I got a lot of emails about light in general after class, which lead to some great discussions at the beginning of the next class period. This isn’t the only example from the first few weeks of classes this semester that has proven the benefit of participating in GPD. I’m looking forward to having class session from my physics of music class critiqued in the next few weeks.

GPD isn’t a replacement for institutional feedback or even conferencing, but it’s providing me with a way to improve my teaching that doesn’t come from the more formal professional development avenues. I’m excited to be a part of this community.

Have you benefited from GPD? Would such a system maybe be helpful in your own discipline? I’d love to hear from you in the comments.

  • Sarah Pierce

    As our students math skills are getting better, I’ve started to notice that some students are reasoning through the math instead of understanding the concepts, which is a little bittersweet. Interestingly, when the math skills were not as good, students really focused on concepts in the hopes they could avoid the math. I’m working on restructuring several of my question series so that the students understand both the math and the chemistry concepts.