Physics&Parsimony

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Archive for the ‘video’ Category

Spend Time, Dig Deep, Think Hard

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“… spend time, dig deep and think hard…” These are words I used in a response to Rick Fletcher’s comment to my last blog post. We had a little back and forth on when videos seemed to help propel student learning. Then it hit me. I have been asking questions about how and when my students engage in deep practice, and “spend time, dig deep and think hard” perfectly describes deep practice. Maybe all is not lost and I do have some tricks up my sleeve that promote deep practice with my students.

Deep practice in the swimming pool is a bit easier to arrange, and I think that this is what frustrates me. We get out the snorkels and devise drills to isolate head, hand and body position. We use the power rack, power tower and speed assist training to isolate explosive motions. We do lots of threshold work and maxVO2 work every week. And we kick, pull with paddles and swim with flippers, isolating specific sub-skills. We film the kids and post the individual videos (with commentary) that they can watch the very same evening they were videoed. The new swimmers get daily stroke work for most of the practice, with one coach totally dedicated to that lane.

I try to immerse my students in deep practice during class, first so that I can watch them (just like I watch my swimmers), second so that I can give feedback quickly, and third so that I can more carefully design exactly how the time is spent. This deep practice consists of doing experiments, solving large problems in small groups and verbally defending their ideas. Several years ago, homework was where I expected my students to put in all of their hardest practice. Now my students’ evenings are a mix of some necessary (but not too strenuous) skill-building and lots of (very strenuous) self-directed practice and remediation. Evening self-directed practice is necessary because I use standards-based grading, and students are required to address missing learning objectives after our initial formative assessments. And it is this particular practice that worries me.

I suspect that my students’ self-directed practice might not reach the level of useful, deep practice for two reasons. First, I see very uneven results. The proof is in the pudding, right? If the kids aren’t getting better very quickly, then the practice is ineffective for some reason (too little time spent? wrong things being done?). Second, I don’t feel that I am giving them enough good ideas for how to engage in deep practice. I’ve just realized that the videos that I have made for my students are being used by at least a few of the students for deep practice, while my original goal was just to give them a little more help.

From my last post, remember that I make one type of video that isolates small, mechanistic skills. When I hear from a senior who has had vectors in math class for three years tell me that she watched my 4 minute “how to move a vector so that you can subtract vectors graphically” video more times than she could count (and subsequently finally understands what vectors are and how to manipulate them), I hear deep, repetitive practice of an isolated sub-skill.

I also make videos where I solve some big bear of a problem where I talk my way through my thought process, starting from models and fundamental principles. When I overhear two sophomores talking about how many times they had to watch that video before they found the one glitch in their thought process that was keeping them from truly understanding conservation of momentum, I am hearing a description of deep practice.

So here was my initial misconception about these videos: I thought that students would use these videos once and learn something. Yet I never hear any of my students say “I watched that video, now I understand.” They might get enough from one viewing to go back on their own, dig deep and think hard, so I don’t think a single viewing is necessarily worthless. Some of my students may only need this kind of small boost. But it is the students who spent time, dug deep and studied the videos who really got a lot out of the videos. And I really think this works because it is their teacher (someone they have a connection with, someone who is connecting their daily experience in the classroom to the subject of the video) who is making the video. A one-size fits all video from someone who has never attended my class probably wouldn’t inspire the same kind of hard work and time spent.

Written by Mark Hammond

2011/06/20 at 09:29

Using Videos to Help Learners

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The media attention garnered by Khan Academy has inspired considerable debate about the efficacy of using videos to help learners.  Some have taken criticism of Khan’s videos (such as this well-reasoned piece from Frank Noschese) as equal to saying videos are incapable of helping students learn. Sal Khan has personally commented on the subject, and at one point challenges others to post better videos. He also gets a little testy later on in the comments, suggesting directly that his critics think video is useless as a learning medium. Yet I think it’s what happens in the video that is important. The fact that video is the medium is quite secondary. The secondary nature of the medium is totally lost on most of the fawning press Khan Academy gets. “It’s video! OMG! It’s a revolution!” Yes. Gag.

I think video can be useful for helping learners. I’d like to set forth here how, when and why I use video (or want to use it more… I’m pretty new at this).

Individualized feedback:

I mark up student work like everybody else. That is, I give written feedback. I am often unsatisfied with my own written feedback, because 1) my writing is messy, 2) the page gets crowded, 3) I am too impatient to fully explain what the student is missing and 4) I suspect my written feedback is often not studied by my students. An alternative that I have used is to write only very limited feedback, scan the student work, then make a quick screencast, pointing at the mistake on the scanned document with my voice-over expounding on what has gone wrong. I can even ask questions of the student, rather than just give the correct answer.

Why do all this when my students and I live nearly on top of each other? The reason is I can quickly knock out four or five short screencasts in the evening before bed or in the morning before class in about the same time it would take to set up a series of short conversations with the kids. And the students tend to watch the videos and then ask really good questions later. These videos do not replace the student-teacher interaction, they make it simpler and often make it deeper when the face-to-face happens.

Mechanistic Instructions:

I make short videos showing how to do things like redrawing a vector with its tail on the tail of another vector, reproducing the magnitude and direction accurately using a protractor. Simple, right? Anyone should be able to do that. At least that’s what I thought until I realized many students were flailing around, unable to translate words and still pictures into action. I’m getting ready to make a video showing students how to use a scale on the page to measure the magnitude of a vector. And how to use a protractor correctly. These are all things that I want my students to be able to do on the summer homework I just sent them. Without the videos, I know that I get a lot more confusion and less learning, just because some very simple steps have not been explained. Sure most would figure it out by themselves, and most actually will! This is a back-up plan for the minority that need it.

How are these videos different from Khan Academy videos? They are different because they closely match the way I want to teach vectors. They are not designed to give any deeper understanding about vectors, they are designed to address small steps that are fairly mechanical in nature. The videos are customized to my style to a degree that a video made for millions can’t be. And the subject matter is chosen to address small problems that I know students will have, based on my in-class experience.

Once this past year, a student had a problem that I didn’t have time to address. She had forgotten how to use scientific notation and this was holding her back. She had learned scientific notation before, but was rusty. I sent her to Khan Academy (even though I cringed a bit at the way negative exponents were explained). Here is what I consider a legitimate use of Khan Academy videos: the student already knows the content, but needs a refresher. If the student were learning scientific notation for the first time, I would not want to present the algorithmic approach that Khan uses (even though he claims to “explain the why,” I find most of his videos very much “do this, then do that” algorithms with little meaning), but for my student who needed a quick refresher, this was the quickest way for her to get it. If I had an extra thirty minutes that day (and they coincided with her extra thirty minutes), a live session with me would have been better, but we got the job done with the help of Sal Khan.

Problem-solving:

Occasionally I make a longer video (or pen-cast) that shows me walking through a tough problem. I do this so the students have a model of solid problem-solving that they can review as many times as they want. I emphasize that just watching a video (or a live lecture) of a problem being solved by someone else will not result in understanding. But the video gives the students a way of getting immediate feedback when I’m not around. This is how we achieve deep practice if I’m not actually in the same room as them.

Can Khan Academy provide this kind of video? I guess it could, but it doesn’t. Maybe it can’t. My problem-solving videos may only work for students who start their solutions from fundamental principles and then move to a determination of what models apply. Other teachers use different approaches… I wouldn’t suggest students outside my school would get a great deal from my videos. Maybe they could, but I won’t insist they could. My students get to where they can understand my videos by developing their own understanding in the lab. If a student went from Sal Khan’s kinematics lectures to my problem-solving videos, I’m pretty sure they would be confused.

Flipping the Classroom:

More on this later, but I haven’t figured out how to do the flipped classroom all that often. I use Modeling Instruction, where the students are already doing in class what proponents of the flipped classroom are advocating. The uses of video mentioned above do save some class time, but it’s not as if I’m giving video homework every night. Or even once a week. I think of using video as a way to be more efficient. Maybe there’s more… I’ll work on it. I am gradually using video more and more, though.

Do you have more ways of using video? Leave a comment!

Written by Mark Hammond

2011/06/11 at 12:25

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