Jun 27, 2012

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.

One Response so far

  1. Joe Wagner says:

    Backpack TV video response to Mystery Teacher Theater 2000 and in defense of Sal Khan and Khan Academy.


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