Gas station without pumps

2012 July 4

Trust your teacher?

Filed under: Uncategorized — gasstationwithoutpumps @ 12:44
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On Robert Talbert’s Casting Out Nines blog, he recently posted about the problems he sees with the Khan Academy.  He is not opposed to the use of Khan’s videos, but he sees them as having rather limited application:

But on balance, KA is a great resource for the niche in which it was designed to work: giving demonstrations of mechanical processes.

I was nodding along with him on most of his points (though I assign somewhat less value to videos as a teaching tool than he does, perhaps because I rarely have the patience to sit through a teaching video).  One of his points brought me up sharply though:

Learning at these levels requires more than watching videos (or lectures) and doing exercises. It takes hard work (by both the learner and the instructor), difficult assignments that get students to work at these higher levels, open channels of communication that do not just go one way, and above all a relationship between learner and instructor that engenders trust.

I protested in the comments

While that relationship is very nice and makes learning easier, it is not an absolute prerequisite of learning.  I have learned a lot from reading and working on my own—doing so is essential if one wants to stay in a technical field for 30–40 years.

If you sincerely believe that real learning only happens with relationships between learner and instructor, you doom most engineers and scientists to very short careers.

 and Robert softened his position to
Would it help to say that learning “works best” when such relationships are in place? Because of course most of us can learn under just about any conditions, but some are more conducive to the learning process than others.
David Wees wanted me to defend my position further:
Do you trust what you are reading? Do you trust the source of the information you are getting? I’d say that if you didn’t trust it, a lot, you wouldn’t bother to even attempt to learn from it, even on your own, so in some respect trust is pretty important.
That got me thinking about how I learn things now, since I don’t trust most of my sources in the way that Robert and David seem to think is essential.  Here is the reply I made:

When I’m learning a new subject, I do trust my sources somewhat, but I generally use multiple sources and check them for consistency.  For some things, I use very untrustworthy sources, but check the stuff I learn against the real world.  For example, I’ve been teaching myself circuits and trying to design lab exercises for a new circuits-for-bioengineers course.  I’ve used probably half a dozen different circuits books (none of which I have at home currently), Wikipedia, manufacturer’s data sheets and application notes, DIY electronic hobbyist sites, and more.  I’ve then tried building each circuit idea that I’m considering for the lab exercises.  When I’ve been relying on a bad source, the circuits don’t work the way I expect, and I look for better explanations of what is going on.

The DIY electronic hobbyist sites often have the simplest circuits and the clearest explanations, but these sources are also often wrong—the simple explanations are not always correct ones, and the simple circuits often fail miserably.  That does not mean that I can’t learn anything from those sites—just that I have to treat anything they say with a healthy dose of skepticism, checking against other sources and against the real world.

So, no, it is not necessary to trust one’s sources in order to learn from them, but one does have to become aware of how reliable or unreliable they are.

I think that there is an important point in the philosophy of pedagogy here: should students trust their teachers and their textbooks? What should students do when they find a discrepancy? How do we teach students how to correct the misconceptions that they have gotten from prior education?  What do we do as teachers when we find out that something we have been teaching is wrong (either subtly simplified or grossly wrong)?

I start out some of my classes telling students that I will lie to them—teaching them simplifications that I know are not quite right, though I believe the simplified models to be useful for understanding.  Sometimes during the course I will point out the limitations of a particular approach we are using, or introduce a more accurate model to show where the limits are for the applicability of the simpler one.  These sorts of “errors” I know how to handle, and I’m usually delighted when a student comes up with a limitation of a model we’re using and points out how it can be modified to be more accurate.  I want the students to listen to what I say and examine it closely—not to blindly trust me to get things right, but to look actively for discrepancies.

I have some trouble with students who come in with simplified models and insist on holding on to them, even when they have moved out of the realm of applicability of the models.  This happens a lot in biology, since the models taught in biology are usually weak and do not cover much of the data.  Students trained in fields with strong models (like computer science and physics) often have trouble with understanding biology, because they want to reason always from the models they have been given, rather than from the data.

Because I mainly teach at the senior undergrad and graduate level, I’ve only occasionally met students who can’t learn biology because of religious beliefs—most of those who can’t modify their religious beliefs or reconcile them with the scientific data have left the field before I encounter them.  I understand that this is a serious problem in high-school classes, though, as students who have been taught to trust their preachers and teachers often have great difficulty in reconciling incompatible teachings.

My advice to students echoes one of Ronald Reagan’s favorite sayings “Trust, but verify”.  (Wikipedia claims that it was a translation of a Russian proverb that was a favorite of Vladimir Lenin, but I’ve not verified that.)  If you don’t know a subject, you have to trust your teachers and textbooks to know more than you about it, but it is always a good idea to verify what they say against other sources.  When it is possible to verify against the real world, that is best of all.

1 Comment »

  1. […] It connects to a very interesting exchange that happened at Casting Out Nines and Gas Station Without Pumps.  Does trusting our teachers make it easier to learn?  Or […]

    Pingback by Try Pressing All the Buttons (or, how to get my students to stop trusting me) « Shifting Phases — 2012 July 20 @ 09:25 | Reply


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