The Ineffectiveness of Science Videos

Monday, March 21st, 2011

The Khan Academy has earned all kinds of praise for its wonderfully clear educational videos, but Derek Muller, who did his PhD thesis on the (in)effectiveness of science videos, explains his concerns:

Please watch the video, before reading on.

So, the surprise punchline breaks down into these five points:

  1. Students think they know it.
  2. They don’t pay utmost attention.
  3. They don’t recognize that what was presented differs from what they were already thinking.
  4. They don’t learn a thing.
  5. They get more confident in the ideas they were thinking before.

The surprise punchline for good students who never went on to teach is this: most people learn little or nothing from school. They don’t get it.

In the physics example, I can see exactly why someone who already knows physics would interpret the video entirely differently from a normal person who doesn’t yet grok elementary mechanics. Force is a well-defined bit of physics jargon that isn’t at all so well-defined for a normal audience. As the ball goes up, its upward velocity — and thus momentum — decreases at a constant rate, passes through zero, and becomes downward velocity — but force, velocity, and momentum aren’t clearly distinct and mathematically defined for normal people. So they follow along and agree that the ball goes up and then comes down. That’s what the stuffy-sounding narrator is saying, right? I already knew that. Jeez.


  1. Aretae says:

    I call it the Discovery Channel effect:

    1. Watch Discovery Channel science program…
    2. Wait 10 minutes…
    3. Explain what you learned.
  2. Jose Silva says:

    When teaching business these five problems are amplified — probably because of the widespread (and wrong) perception that technical business material is commonsensical or trivial. And, if the instructor follows the path of lower resistance (which many do and get rewarded for), these problems get even worse.

    I propose some actions to counter these problems.

  3. Isegoria says:

    I suppose those problems are further amplified when teaching business by the fact that business undergrads aren’t exactly sharp, as a rule, and MBA students aren’t exactly humble.

  4. Sconzey says:

    Interestingly Galileo presented his theories through a dialogue between three characters, one of which presented the Aristotelian (and incorrect) case, and was gently corrected by the other two.

  5. Isegoria says:

    Excellent point, Sconzey. The ancient rhetorical tool of presenting a dialog did exactly what a good science video should do — think out loud.

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