VideoLabs as Instructional Videos

Today I made a submission to an instructional video contest/program called EDU Guru, sponsored by YouTube, Google, and KhanAcademy (sorry... not gonna link those). Being somewhat of an instructional video skeptic, I tried to use this as an opportunity to illustrate the value of a genre of instructional video that would be less at odds with inquiry instruction. The video I submitted is here:

There's also a companion video which shows the force meter readings for 65 mph, so a student who makes the prediction could then check it against actual measurements. I included a link down below¹, but I recommend collecting the data and making the prediction yourself before ruining the surprise!

I've called it a VideoLab in conversations with friends. My hope is to create quite a few more of them this year. The relationship depicted here, of course, is less central to most introductory physics courses. We generally ignore air resistance precisely because it's messy, as the uncertainty in these measurements shows². But I think it's actually pretty remarkable how even a system as gnarly and variable as this one can fit a simple model (as long as you give yourself some healthy error bars). In any case, the model of an "instructional video" that contains everything you need for collecting and analyzing quantitative data on a relationship could be quite powerful. It's no substitute for hands-on work, of course, but students who wouldn't otherwise have access to a proper physics lab (or simply missed class on lab day) could benefit greatly. Imagine if a whole slew of VideoLabs were accessible online... How 'bout it, folks? #videolab?

There's at least one precedent for using video this way, in the wealth of videos created and hosted by Rutgers Graduate School of Education (where I am currently a student!). Each of the videos on this site is designed to serve as part of a cycle in which students observe a phenomenon, form a hypothesis that explains what they've seen, consider the implications that their hypothesis might have for further observable data, then make a "testing observation" to see whether what's depicted in the video agrees with the prediction they made. The video I've made here is similar, but my goal is more to present students with data that can be analyzed quantitatively, in a style similar to the analysis of data collected during a paradigm lab of a Modeling Instruction unit.

I still plan on making a few more companion videos, including a qualitative "observation-oriented" video that could be used for asking, "What could we change? What could we measure?" before any instruments are shown. I have a lot of footage of stuff sticking out of my car window, and I want to make good use of it!! Maybe the next step is just to upload a bunch of raw footage set to a soundtrack of Empire State of Mind. Concrete jungle where dreams are made of... videos about air resistance! So that's how the line is supposed to end!



¹ 65 mph check video here!

² I also did the same experiment with a flat disk instead of a plastic bag (a cd, as you can see from the picture above), but it's a lot less fun to watch and the numbers are no less messy. I'm planning on editing that together too though, for comparison's sake, when I get a moment.

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Instructional Resources in Programming

Khan Academy's new computer science platform is a refreshing deviation from the lecture-based curriculum resources previously offered by Khan, and has the potential to further encourage the exploration of programming as a tool for teaching creative problem solving.

Khan Academy just unleashed a new computer science platform. As somewhat of a KA skeptic, I have to admit that I was doubtful when I got the news, but on first glance it seems like this thing totally rocks. Before I get into the thick of some thoughts I've been having about instructional videos and programming, let me identify a few things that they're getting right in a most beautiful way:

• The platform is elegantly constructed, and allows for instantaneous feedback on how a change in the code has changed the behavior of the program. (...and the sliders on numerical values are awesome!)

• The activities are almost completely open-ended. Users are free to mess around with the existing program in any way that that want, or to start their own program fresh. Some of the benefits of this approach are outlined in a manifesto/blog post by KA Javascript-dude John Resig.

• Instructional narration is left off most videos. When narration is included, it's entirely optional unobtrusive for those inclined toward a more playful approach. Also, the narrator of the videos is a woman - isn't it about time we razed this CS boys' club to the ground?

I've suggested before on this blog that programming can be an ideal environment for problem solving. A programming environment offers explicit connections between cause and effect, provided the programmer is able to navigate a ruthlessly picky syntactical landscape. In other words, to succeed at programming, a student needs to both become familiar with the details of the language AND apply this language conceptually in creative ways to solve problems. The role of instructional videos in the pedagogical balance of concepts and processes is hazy, but this latest resource hits closer to the mark than anything I've seen from KA.

I found myself thinking about this balance a few months ago, when I made a few instructional videos about programming in Python. In the following video, I've tried to provide instruction on some commands required to code a "guessing game" (specifically, the use of the conditional statements if and while), but withhold some details that are necessary for completing the task. In making the video, I remember struggling with the puzzle of where to draw the line between giving student the support they need to go forward and leaving some freedom to explore the programming challenge as an outlet for creative thinking:

Rather than demonstrating outright how to complete the task, my goal was to provide what a student might need to get started programming and troubleshooting. I tried to provide a concrete foundation for why the basic design of the program is valid, and to model good programming behavior in my presentation. (For example, I put the program together in small chunks, frequently testing the individual chunks to confirm that they did what I expected them to do, and I consulted the internet for the answer to a specific question about Python syntax.) It was interesting to me to compare my video to the new KA tutorial on if statements, since the KA tutorial does some things much more effectively than mine. For example, the KA tutorial targets the if command explicitly, making it a more efficient resource than my own somewhat rambling contribution.. More importantly, the KA tutorial introduces the NEED for an if statement before the introducing the command itself. This seems similar to the Modeling Instruction tenet of introducing and defining a concept before giving it a name.

Some time ago, a math teacher in New York City created this excellent video, called "What if Khan Academy was made in Japan?" to contrast KA's "Watch. Practice. Learn." approach with a more effective "Struggle. Struggle. Learn." approach. That is, in countries like Japan and Finland, where math education programs are more successful than most programs in the US, students spend most of their class time working through difficult problems, rather than being told how to solve such problems by their teacher. At the end of the video, we're given an example of what a more effective instructional video might look like.

The main takeaway from this video is that learning takes place when students struggle with questions, not when they sit through an answer. While it's clear that instructional videos are useful for absorbing procedures, they have questionable value as tools for facilitating real conceptual learning, and for this reason most of Khan Academy still stands at odds with inquiry education. Drawing a line between concepts and processes is perhaps easier in programming than in math, but the KA Computer Science platform is a refreshing change, even from previous KA programming resources.

One hugely promising feature of the new KACS platform is that there aren't really any questions and answers to begin with, so it's up to the users of the site (teachers and students alike) to decide how to direct this sandbox experience. In the spirit of guided inquiry, I can imagine a series of "mod prompts" designed to identify unique or significant elements of the code. For example, in an assignment based on this cool little KA program that draws a radar screen from ellipses and lines in a rotating reference frame, a teacher could assign various challenges,* from "Change this program so that rotating bar is shorter in length" to "Change this program so that the trail on the line takes more time to fade away." Solving either of these prompts requires the alteration of only one value in the code, but identifying which value needs to be altered can be a non-trivial conceptual challenge. (I struggled with that second question for a little bit, but figuring it out gave me a much clearer picture of how the program was constructed. I'll leave you to figure it out on your own!!)

I'm still fascinated by the potential of programming to serve as a tool for exploring creative problem solving. I'm struck by the degree to which the environment adopted by KACS, which emphasizes the modification of existing programs over building programs from scratch, eliminates the need for a lot of direct instruction on programming language process. As KACS goes forward, I hope that we'll see more programs and tasks emerge, similar to how an educational community has been built up around Python. If the inspiration behind this branch of Khan Academy someday finds its way into the other curriculum resources they offer, Khan Academy users will be better served indeed.



*A few of the introductory programs on the KACS site include prompts to Change this Program, but this is (for the time being) left off most programs. I'm not sure whether I think it'd be a good thing for these prompts to be a more dominant part of the KACS experience. Certainly it would make for a more self-contained curriculum, but it may also excessively limit creativity. I guess we'll have to wait and see whether this expands as KACS grows further.

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Concepts vs. Processes: Still More Thoughts on Khan Academy

Until Khan Academy attempts to differentiate between concept- and process-based learning, Sal Khan's instructional videos will continue to stand at odds with inquiry-based education.

Khan Academy is in the news again! Or maybe it never left... Ok, ok, I'm sorry for contributing yet another KA post to the education blogosphere (This is my third already, and I'm far from the worst offender), but this stuff's been on my mind a lot lately!

Recently, two math teachers posted a critique of a Khan Academy video, thus stoking the flames of an endless debate over the educational value of instructional videos. This video critique, dubbed Mystery Teacher Theater 2000, or #MTT2K, has received a lot of attention, and even spawned a contest to create the best KA critique. I'm proud to say that I've made my own #MTT2K video, which is embedded below.* Though Sal Khan's response to this criticism has been encouraging, I'm concerned that much of the debate surrounding Khan Academy obscures a subtler examination of the role that instructional videos should and should not play in a "revolution in education."

A lot of the Khan-bashing that gets tossed around is focused on aspects of Khan's videos that are unclear, poorly presented, or downright incorrect. Unfortunately, plenty of the KA videos can be criticized in this regard, but it's far from the majority, and Sal Khan's positive response to the #MTT2K project made it clear that he recognizes the benefit of rooting out and correcting such mistakes. As for the the gaffs, some fans of KA have said that Khan's occasional typos and stumblings make him a less intimidating tutor, and Khan is generally showered with praise for the clarity of his explanations. The majority of comments posted below his videos reveal as much. But for my money, the most severe criticism of Khan Academy has nothing to do with the clarity, or even the accuracy of a given video. Within an inquiry approach, clear and accurate explanations are actually a threat to the learning process.

Now, I freely admit that plenty of valuable information-gathering takes place through methods that aren't based in inquiry. For communicating the ins and outs of some accepted process, the instructional video medium is a fantastic way to create and store decent explanations. When I want to know how to apply some obscure filter in a photo-processing application, I don't spend much time performing experiments to arrive at the technique by inquiry. I go find an instructional video on YouTube that was made by some 13-year-old!! But truly process-based tasks are a tiny fraction of the learning that we're asking of our students. The great fear about Khan Academy is that it encourages students to see everything they're learning - addition, multiplication, algebra, calculus, free-body diagrams, conservation of energy, or even analyzing the actions and impulses of human beings caught up in a momentous event - as process-based tasks.

Is it unreasonably picky to insist on the sanctity of the inquiry process? 30+ years of Physics Education Research suggest that it isn't... The human mind is notoriously excellent at fitting in new explanations between the cracks of the things we think we know already, just so we don't have to throw out the old stuff. In my own contribution to the #MTT2K project, I tried to portray this phenomenon at work.

Admittedly, Khan took on quite a challenge in attempting to lecture about acceleration, a topic rife with nuance and levels of partially-correct understanding. The voice-over by the "student" shows how the video reenforces many common preconceptions, including but not limited to:

   • equating a clock reading (denoted by t) with a time interval (denoted by ∆t)
   • equating the direction of velocity with the direction of acceleration
   • misinterpreting common units of acceleration (m/s², or in this case, miles/s²)

Furthermore, Khan spends most of his lesson discussing unit conversion, a process-based task as fantastically mindless (and perversely satisfying) as painting a wall. Like wall-painting, it has to be done correctly, and a target instructional video could accomplish this instruction effectively if it wasn't folded into a lesson on acceleration. Indeed, Khan has made at least two videos (1, 2) that explicitly cover the subject of unit conversions, and together they've been watched over 200,000 times. Unfortunately, both of these videos ramble through the peripherally related topic of metric prefixes, fail to sufficiently demonstrate why multiplying by a "conversion factor" doesn't change the quantity represented, and do not contain examples of more complex conversions (How many m³/s are in a cm³/hr?), but these are subtleties compared to my main criticism of Khan Academy. We might be able to effectively offload to a video the task of teaching students to convert units correctly. (I couldn't find a video I'd want to use on Khan Academy today, but I might find it on Khan Academy someday.) However, there will never be a curriculum of instructional videos that builds up conceptual understanding of acceleration.**

There are more processes than just unit conversion involved in constructing a working model of acceleration, and instructional videos may have a role to play in students gaining familiarity with them. Using computer-graphing software is certainly one example. However, try to extend this list much further, and you see that making an explicit distinction between concept- and process-based tasks is pretty tricky. Is calculating the slope of a velocity-time graph process based? How about interpreting the meaning of this slope? How about linearizing a position-time graph? In any case, how can we tell if our video-curriculum has been effective? Purely process-based approaches to solving physics problems can be quite successful according to some measures, and assessments that truly discern correct conceptual understanding are a challenge to both develop and implement.

Luckily, our goal isn't to compartmentalize pieces of our curricula into "concepts" and "processes." The bottom line is that true learning requires students to actively make this distinction for themselves, and to approach solving new problems like a thoughtful human being, not a knowledgeable robot (damn those 100% success rate robots...). If this distinction is to be made by students, it has to made by teachers first, whether they're in person or online. So far, Khan Academy hasn't shown an interest in exploring this.*** Until they do, Khan's videos will continue to stand at odds with inquiry-based education.

*Though I made my video before I knew that there was going to be big prize money involved, it's fantastic that other teachers now have some more incentive to voice their opinion. Bring on the competition! Show us what you've got!!

**Do I truly believe that no videos will ever contribute to learning something conceptually? A definitive claim like this would require a rigid distinction between concepts and processes, which is impossible and sort of pointless. Regardless, I'd suggest that any conceptual understanding that comes from watching a lecture is a result of concept "construction" by the viewer, not "instruction" by the lecturer. Just as we've seen with research into the efficacy of in-person lecture courses, we can't rely on this concept construction taking place in most students.

***As I mentioned in my last post about KA, I got a chance to ask Sal Khan a question about the role of instructional videos in an inquiry process. He was somewhat dismissive of the criticism, suggesting that evidence against the benefit of instructional videos wasn't evidence against the benefit of HIS instructional videos. Specifically, he used an analogy about sugar pills and cancer research to suggest that his pills might just be the cure for cancer.

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