17 November 2011

Link of the day: Khan's Academy

Lately, I've tired of TED talks. They were bold and exciting when they first appeared online (3-5 years ago?), but now people just seem to be selling their ideas whether they are merely good or truly brilliant. It's important to have inspirational meetings, but I think they should also be authentic and realistic.

There is one recent TED talk that I do like very much. Salman Khan, a former hedge fund analyst, spoke about how video can re-invent education. Originally, Khan recorded videos to help tutor his cousins in math. He posted the videos on YouTube and left them publicly available, in case someone else might find them useful. His cousins told him that they preferred their "virtual" cousin on video than the real thing! They found the video less intimidating because they could stop and repeat it without appearing stupid; they could learn at their own pace.  Other people discovered Khan's videos and gave him so much positive feedback that he quit his finance job and started producing videos all the time. (Khan does all the math and science videos, and he hired experts to do the videos on humanities subjects.  The scope of this project is astounding: 2000+ videos.)

That alone would have been an outstanding accomplishment, but Khan didn't stop there.  He tried to track learning outcomes.  He associated each video with a particular concept and made tree diagrams showing which concepts were prerequisites for other concepts.  Khan calls this a "knowledge map."  Students can work on modules.  When they get enough problems from the module correct, they can move onto another module.  When they master the prequisite modules, they can move on to a more advanced module, and so on.

This systematic tracking of the student's progress is invaluable to a teacher in charge of 30 students.  The teacher can see how the class is doing.  Moreover, if a student is struggling with a particular module, the teacher can find another student who mastered it and have that student teach the other one.  Peer learning!  (I discussed this topic in an earlier post about a Harvard professor struggling to teach first-year physics.)  Now, at least one school district (in Los Altos, California) is trying out Khan's system in the classroom.

When the system was used in the classroom, it showed that different people find different concepts easy and different concepts hard.  In Khan's words:
Because every time we've done this, in every classroom we've done, over and over again, if you go five days into it, there's a group of kids who've raced ahead and there's a group of kids who are a little bit slower. And in a traditional model, if you did a snapshot assessment, you say, "These are the gifted kids, these are the slow kids. Maybe they should be tracked differently. Maybe we should put them in different classes." But when you let every student work at their own pace -- and we see it over and over and over again -- you see students who took a little bit extra time on one concept or the other, but once they get through that concept, they just race ahead. And so the same kids that you thought were slow six weeks ago, you now would think are gifted. And we're seeing it over and over and over again. And it makes you really wonder how much all of the labels maybe a lot of us have benefitted from were really just due to a coincidence of time.
I found this very interesting.  I'm guessing that a lot of teachers and coaches know that student learning is much more complicated than "gifted" and not gifted.  It's nice that Khan can actually provide hard evidence establishing this fact.

Khan's work is amazing and inspiring. I do have a few questions. Using technology to tailor education is not a new idea. Why did Khan succeed? Is it because students are more comfortable with technology compared to students of the past? Why is video better than a textbook? A textbook is also non-intimidating and self-paced.  Maybe it's because Khan is a great tutor who is both a talented teacher and entertainer?  (I briefly viewed one of his videos and he seemed funny and charismatic.)  In an ideal world, each student would have a one-on-one tutor.  This isn't realistic.  However, if we have a great tutor like Khan and he makes free videos available to anyone on almost every possible math and science topic from kindergarten to high school, this tutoring database is a pretty good, though imperfect solution.  It's reminiscent of an idea in artificial intelligence.  You can have a computer that isn't smart in the human sense, but if you program it with an astronomical amount of information, it can be very useful.

I think that doing online homework is becoming more popular as teachers realize that there is simply not enough time in the classroom to do everything.  There are a lot of things students can do on their own with a "computerized" tutor.  By "outsourcing" this teaching and doing it outside the classroom, the human teacher has more time to teach things that are hard for computers.  Like having students discuss problems together.  Or showing how many seemingly disparate concepts unify into a larger concept.  Or doing hands-on science experiments.  I know that for first-year physics courses, some universities assign online homework several times a week.  This forces students to read the book and work on problems at home so that the lecturer can spend time explaining concepts rather than writing 20 equations on the blackboard.

What Salman Khan is doing is incredible work and I wish him the very best.

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