Roberta Tevlin, Danforth Collegiate, Past President of OAPT, Editor of OAPT Newsletter roberta@tevlin.ca
Seeing deeper, watching videos
One of the most valuable resources for Ontario physics teachers is now available on the OAPT website. It is a set of videos showing the grade 11U and 12U physics courses as taught by Chris Meyer - our V.P. of Teaching and Learning. Each video is a single lesson (edited to 15-30 minutes) and is accompanied by a student worksheet and a short description of the pedagogy and physics presented. 
Chris has already generously presented his materials in workshops, articles, classroom visits and on his website. Chris explains his motivation for adding this new element. “People are not blank slates: when someone enters a physics classroom they bring with them a wealth of life experiences that they use to make sense of what they see. Often, what they get out of your careful presentation is very different from what you hoped or think is obvious and clear. To help teachers see past the familiar, I have created videos of my classes in action that include detailed pedagogical commentary, helping to explain what is seen. The videos allow me to present the rationale for the different stages or facets of the lesson as the students confront them. This gives a very rich and immediate context for the pedagogical strategies being used.”
Freefall: Students confronting preconceptions in physics
This sounded like a great idea, so I looked at the grade 11 lesson on freefall as an example. This lesson looks at what happens when a ball is tossed up. What happens at the top? Does it stop there for a short time or not? He takes a full class to prepare them to answer the question. 
The students start by exploring falling motion and at 13:22 the students speculate about what happens at the top. (It is impressive how deeply on-task the students are!) At 15:48 we learn that the majority of the students think that the ball stops briefly at the top. Next they look closely at the evidence from a motion sensor and Chris’s comments help clarify the importance of helping the students distinguish between the different events and intervals. Just before the end of the class (27:30) in the edited video) he asks the class “Does the ball remain with a velocity of zero for some interval of time?” Almost immediately you hear a student say “yes” and then the students’ discussions get very quiet and tentative. They have realized that there is a conflict between their ideas and the evidence. As Chris writes in the comments, “We are finally ready to address the issue of remaining at rest at its highest point.”
What pedagogical preconceptions might a teacher bring to this video?
If I had watched this video ten years ago, I would have come away disappointed, and I probably would not watched any of the other videos. It was a good lesson, but I didn’t learn anything new. I was already familiar with the demos and the lesson was just students filling in worksheets for the first half and then a lecture with PowerPoint slides and a motion sensor graphs for the second part. Well, I have learnt a lot in the past ten years, including how much more there I have yet to learn about teaching. The new me found the added commentary really valuable. They helped me recognize specific examples of general PER concepts and how the worksheets were structured to increase learning. This particular lesson was especially good at pointing out and dealing with the many difficulties students have when interpreting graphs.
The art of discourse
Encouraging good student discourse is one of the most important aspects of PER. In these videos you can eavesdrop on these discussions in a very deep way. Chris says that “In the videos, I am able to explain many things about my conversations with students while these conversations unfold: the purpose of the conversation, why I choose to ask particular questions, how I lead students though certain lines of reasoning, how I anticipate their conceptual difficulties and help resolve them, and my careful choice of physics language.” I am constantly surprised by what students think and I find it hard to resist the option of just telling them how and why their ideas are wrong. It is so much faster – but it doesn’t result in lasting change. It is very hard to change a student’s preconceptions of physics and it is very hard to change my preconceptions of teaching. These videos are just what I need to help me change.
