Learning from Lectures

Here's a short YouTube video that shows we should be very wary about what we take away from any given lecture.

That is, more than likely we simply take away our prior misconceptions plus a stronger belief that we know the lecture material.

I believe a similar conclusion is true about simply reading the posted solutions to problem sets, without trying to work through the problems. That is, we all too easily can read the solutions and think, "Yes, those answers makes sense. I could have solved those."

Here's another video about trying to teach you to feel Newton's third law "in your spleen".

In the latter video I think the common misconception that people are using is likely based on another belief, specifically, if we stand on the moon then gravity feels less strong than on earth (the number one-sixth may come to mind). We've all seen enough videos of astronauts gently bouncing around on the moon that we feel this "one-sixth" belief in our spleen.

The second video points out that the typical person's generalization of the one-sixth belief to the mutual gravitational attraction of the earth and the moon is wrong. The generalization misses the fact that the one-sixth belief is based on a situation which uses the same test mass on both the earth and the moon (namely, you), rather than different test masses (i.e., the earth in one case and the moon in the other).

Pop Quiz

There are several possible conclusions to this (select all that apply):

  1. Lectures, tutorials, and solutions to problem sets are useless for learning.
  2. Our CSC373 lecturer is useless (we could learn anything if the material was presented as clearly as that video on Newton's third law).
  3. A good lecturer should anticipate common misconceptions and explicitly try to explode them.
  4. We should be wary of our own beliefs about what we know and what we have learned. Getting additional evidence about what we know, say by working through problems, is critically important for evaluating and recalibrating our beliefs.

Pop Quiz: Possible Answers

In the same order as above:

  1. Unfortunately, yes, they can all too easily be useless. It depends partly on how we, as members of the audience, participate in viewing and consuming the material.
  2. Interesting hypothesis.
  3. Yes. But personally I can say that when I lecture I don't manage to anticipate everything, and therefore I feel it is important to get questions from the audience. Moreover, questions that you formulate after you, as an audience member, make a serious effort at working out problems are likely to be even more useful for your learning, since they can highlight key issues that you are having with the material.
  4. Buzzkill.