Preclass learning

In my recent post NPR reports on peer instruction, I conjectured that a lot of the gains of Mazur’s peer instruction came from getting the students to interact with the material before class.  Although there may well be other aspects of Mazur’s pedagogy that are as important or more important, many teachers are looking at how to get students to read and think about material before class.  It is much more productive for a teacher to be clearing up confusions in the mind of someone who has already started thinking about a problem than trying to get them started from nothing.

Joss Ives, on The Science Learnification blog had a nice post on this today, Learning Before Class Strategies – Quick Update, which included pointers to  other blog posts and articles by various people about pre-reading.

Unfortunately, the data from Joss’s own class do not show any correlation between completing “pre-lecture and checkpoint assignments” and the final exam scores.  It is not clear whether this means that the pre-reading was not effective, or whether the scoring on the pre-class assignments was measuring the wrong thing.  It was an effort measure, but it may well be that the students were just going through the motions of doing the pre-reading, and not actually engaging with the material.

Or maybe students were only reading the material once, in which case it may not matter much whether it is before or after the class in which the material is “covered”.

My own experience trying to learn physics this fall with my son is that I learn very little from reading the book—I have to work several exercises to get the ideas firmly into my head.  The book (Matter and Interactions) has several places where the reader is supposed to stop and think about an example, but I rarely find myself doing so.  Only when I’m working a problem “for real” do I actually think in much detail about the models and formulas.  Sometimes the formulas stick in my head without much effort, but other times not (I particularly have problems with arbitrary constants like ).

So perhaps the secret is not pre-reading, but discussing homework problems after students have struggled with them a bit.  That is the approach our home-schooling class is taking, where we spend our 2 hours a week either comparing solutions to homework problems (and clarifying any confusion brought up by the problems) or doing a lab.  I find the lab classes more fun, though they take more prep time, as I have to design and build or buy whatever equipment we need.  I just got a pair of “photo interrupters” from Sparkfun, together with breakout boards that I hope we’ll use next week for timing the period of a circular pendulum to do Newton’s measurement of .

Comparing solutions has turned out to be useful, even when we have all made the same mistake, because we talk through the method and compare intermediate results as well as the final result. On one mass and spring exercise in Chapter 4, I noticed that we had all left out the force due to gravity, which happened to matter for that exercise.  We re-worked the exercise in class, and got a slightly different solution.