YouTube Frame by Frame

I've been looking for a while for a way to watch YouTube videos frame by frame - to encourage rough quantitative analysis of videos directly online without loading them into a video analysis program like Logger Pro. I've had some success with encouraging students to measure position by putting a ruler directly on their screen - but until a few days ago it was quite difficult to get useful clock reading measurements from the YouTube player.

This exercise is MUCH more powerful now, thanks to a simple online app called RowVid, originally created by Calum Eadie, Andrew Ratomski and Jack Lawrence Jones at an Entrepreneur First Hackathon to help rowers analyze training and race videos. Since then, it has developed into general purpose player for frame by frame and slow motion playback of any YouTube video. When I first stumbled across the player, I got in touch with Calum by Twitter and mentioned to him that the player would be even more helpful for physics classes if it displayed the clock reading of the frame. He made this modification in a matter of hours - AND included in the display an estimate of the uncertainty of the clock reading! In a follow-up email, he mentioned to me that he's "keen to hear how it's being used and are very open to feedback from teachers on how to make it better. Get in touch by tweeting @CalumJEadie." This invitation is open to anyone, so please don't hesitate to make your comments and suggestions known!

A ruler on the screen is perhaps not as accurate as point-by-point video analysis, but it's also much less black-boxish. Students are forced to declare their own reference point and positive direction by placing the ruler on the screen. They see first-hand how to think about a "reference point" when the camera is moving along with the subject, and forced to think about what reference lengths they might use in the frame to scale their measurements to usable values. In other words, they have to everything that they have to do in real video analysis software, but they have to do it by hand - and thereby come to terms with why these steps are important.

For example, one of the essential elements of the "Constant Velocity Particle Model" unit in a Modeling Instruction sequence is determining whether the analytical tools in the model are useful for describing the motion of an object. In my ninth grade class, I've shown students following video of sledders at Brooklyn's Prospect Park with the following prompt:

Choose a sledder in the video. Is the CVPM useful for describing the sledders motion? Collect and graph position data directly from the video to defend your answer with evidence. If you can, estimate the instantaneous velocity of the sledder at one clock reading.



Now I can link directly to the video in RowVid's frame-by-frame player, so students simply click on the link to begin analyzing the motion. Here's a picture of me collecting data on the motion of a sledder in the video. 

I chose somebody on a yellow sled who whizzes by at about t = 13s. When I assume that the sled is about 1.2m long, I get a constant velocity of 5m/s for the 1s time interval. Seem reasonable?

What applications do you see for frame by frame video analysis in your classes? Is analyzing "real-life" motion a theme in your class? What skills does this require that solving "constant velocity" problems from a book or worksheet don't address?

FYI - RowVid is currently working on a version of the app focused specifically on the Sochi Winter Olympics. Let's hope that there are some clips where the camera is steady!

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Practicing Struggle at Home and in Class

Encouraging students to practice struggling has the potential to promote perseverance that can carry over into life pursuits unrelated to physics class. But the context in which this struggle takes place will influence whether students associate it with success or repeated failure, and this can have great implications for how they approach new challenges in the future.

Since I first began teaching, I've tried to make "practicing struggle" an important element of my classes. This was partly a matter of necessity, since concepts would sometimes take weeks to develop and students would have to cope with "not knowing" answers to some very central questions as we slowly worked toward more sophisticated understanding. When I came across Modeling Instruction, it seemed to fit in nicely with this emphasis. I'd interpreted the focus of Modeling to be on building physics understanding from scratch through experiments and analysis, and I knew that this would take a lot of struggle and failure along the way. Invariably, I assumed, this would mean plenty of learning from failure, as well as learning to fail, along the way.

I tried to emphasize this to my students again and again. After completing The Marshmallow Challenge on the first day of school, I posted the diagram on the right on the projector and we talked for ten minutes about what it could mean for our class. I included the diagram on a handout explaining my policy of standards-based grading. I taped a copy to the back of my gradebook, and I'd hold it up when new understanding was emerging from our conversation about a tricky new concept that no one had grasped the first time around. When I used a homework assignment to introduce for the first time a problem that required a new concept or technique, I emphasized that students' only responsibility was to TRY. Even if they didn't necessarily SUCCEED or LEARN much the first time around, we'd struggle in small groups and struggle as a whole class until we'd figured it out. But to my great dismay, most didn't seem to become any more comfortable with approaching new ideas in this way, even after months of practice.

I've long been convinced that Physics First is as much about teaching critical thinking and problem solving skills as it is about teaching physics, and perseverance through confusion and frustration is clearly a crucial part of this. I'm certainly not alone in focusing on how we might better develop such character-related skills. Some schools have gone so far as to issue character report cards to assess how these traits are developing, encouraged by psychologists' study of the predictive power of traits like "grit" on performance in and after college. By assigning homework containing material that students hadn't worked with in class, I hoped that I was giving students an opportunity to practice their perseverance, and thereby develop "truer grit." But morale among my students was quite poor much of the time, and the pace of the class has been extremely slow. For a while, students frequently expressed frustration that they never knew what to do on homework, that they were endlessly confused, that they couldn't tell when we reached consensus in class discussion, and worst of all that they couldn't even tell when their own thinking was on the right track.

Practicing struggle? Check. But it was clear that my students hadn't been benefitting from this practice as I'd hoped they might...

I have a colleague who, like fellow blogger Kelly O'Shea, is convinced that homework as it's traditionally assigned isn't effective. My colleague teaches two sections of the "Advanced" Physics First course, and rarely assigns required homework. Citing arguments by Alfie Kohn, he feels strongly that students should be free to do whatever they need to do outside the class to succeed, and free to make these decisions on their own. Kohn's arguments are indeed convincing, and my students' comments echo some of his conclusions precisely. In a 2006 article, Kohn wrote about homework:

It isn’t of any use for those who don’t understand what they’re doing.  Such homework makes them feel stupid; gets them accustomed to doing things the wrong way (because what’s really “reinforced” are mistaken assumptions); and teaches them to conceal what they don’t know.

However, many of my students in the "Regular" physics sections lack the perspective to recognize when they need more practice, or the maturity to prioritize this practice when it's not due the next morning. Required homework, if it's not graded for correctness, can provide some much-needed guidance and scaffolding of how one might spend time effectively outside the class. I agree with homework critics that busy work promotes a false sense of security (or worse), but for a ninth grader, total freedom to choose when and how to engage with a course can be quite crippling. My students were generally embracing the guidance I was trying to provide, but despite my best intentions it was clear this guidance wasn't nearly as effective as it could be. Rather than teaching students that struggle could be rewarding, valuable, and even enjoyable, I seemed to be teaching them to dread encountering a new idea for the first time.

In my simple sequence of 1) personal struggle, 2) small group struggle, 3) whole class struggle, the most confusing and difficult stage of the process has been taking place in an environment where a student can feel alone, insecure and vulnerable. In this context, individual struggle comes to be associated with fear, anxiety, and anger (the list goes on), all of which are detrimental to real learning. If my goal is to teach students to be comfortable with their confusion, this initial stage has to come in an environment they have a fighting chance of actually building confidence. Working with others in small groups is beneficial not only because more ideas are brought to the table, but also because students see others like themselves break through from confusion to understanding. But solidarity can cut both ways: students can band together to work together to puzzle through a new idea, or they can feed off each other's anxiety and confusion. This stuff doesn't make sense to anyone... Why should I even try? is a fire I've had to put out many times this year, but it's almost always come at the beginning of a class period, when students have all wrestled with a challenging new idea on their own the previous night.

This is not to say that students shouldn't be asked to struggle with new ideas on their own - quite the opposite. If struggle is going to be developed as an individual skill, students have to practice struggling individually. To some extent, this will happen with a well-designed practice assignment, where students have to apply and expand on work that began in class when tackling a new problem at home. Moreover, after students have practiced struggling "class first" for a few months (or more, depending on the students), they may build up confidence that can be directed toward working with brand new ideas on their own as well.

We want students to embrace and enjoy the process analyzing a tricky new situation in an inquiry-based physics class. Since the first stages of this process can sometimes resemble a game of pin-the-tail-on-the-donkey, it's reasonable to think that the teacher should be there to at least point them in the general direction of the donkey and put the tail in their hand, or that other students should be there to offer suggestions and cheer them on. I'm convinced that the ability to work through confusion and emerge with better understanding is a skill to be honed through repeated practice, and I've come to see that the early stages of this practice are crucial in the development of the skill. But if students are going to embrace the cycle of "TRY - FAIL - LEARN - REVISE - SUCCEED" they need to associate their struggle with success, not repeated failure. Otherwise, there's simply no incentive to bring themselves to new physics assignments again and again. Worse yet, there's no chance of building perseverance for life pursuits that will take much longer to develop than any physics concept.

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