Re: What Flows?

["Paul Camp" <pjcamp@coastal.edu>]

> Paul counters:
>
> > I don't think anyone has suggested deliberately lying to students (at
> > least, I hope not). My reading of this discussion has been more in
> > terms of a recognition that a simple assertion of a fact without a
> > context within which the student can see that it is a necessary one.
>
> I thought I had given you a perfectly good context within which the
> student *must* use the concepts correctly to get the correct answer.
I thought of it (see below) as a context within which the student can 
discover what the correct concepts are.
 
> > In other words, a student learns primarily (if not exclusively) by
> > discovering that his/her current conceptions have failed in analyzing
> > the current problem and then trying to replace them with more precise
> > and useful conceptions. This is in fact exactly the thrust of the
> > example you have given in which a hypothetical student confronts an
> > inconsistency between two colloquially held ideas. THEN you have an
> > opportunity to teach but before that confrontation occurs, most of
> > the time you do not. It goes in one ear and out the other as you
> > haven't got any phenomenon for your words to latch onto in the
> > student's mind.
>
> Since you are going to introduce the concepts anyway, what is to be
> gained by introducing the wrong ones first? I think the answer is
> that nothing is to be gained. The student will never understand the
> resolution of that particular paradox (the adiabatic equilibrium of
> the atmosphere) without the correct definition. Would you say "As the
> air rises it loses thermal energy" or "its thermal energy decreases"?
> Would you say "There is a flow of heat out of the air as it rises"!?
> All of those are, I hope you will agree, very wrong. Please tell us
> how you are going to reconcile this apparent contradiction using the
> flawed concepts you claim are satisfactory for use by beginners.
>
>
> Leigh

If you read back over what I wrote, I never made that claim. In fact 
_I_ am _not_ going to reconcile the contradiction. I am instead going 
to ask my _student_ to do so. Learning takes place in the mind of the 
student, not the teacher. Why then should the teacher be the only 
active one in reconciling this conundrum?

Again, I think there is a bit of missed communication here (either 
that or you are setting up a straw man but I don't think you would do 
that). The argument is not over whether one should introduce flawed 
ideas and then modify them over time into more nearly correct ones 
but rather over how one should go about introducing correct (or 
nearly correct) ideas. If I have to start with the best physics I 
know, then I would have to start my mechanics class on quantum theory 
and that would be silly. Instead, I have to build outward based on 
the flawed ideas that _the students bring with them_. To do that, I 
have to present them with a series of situations in which those 
preconceptions _fail_ and then ask the _student_ to resolve that 
failure.

Eventually, this of course requires the introduction and consistent 
use of rigorous terminology. After all, language is the medium in 
which we think, like a wave in water, and if the language remains 
sloppy the thinking is more likely to be sloppy as well. In fact, 
some have argued that thought is really little more than linguistics 
(e.g. Julian Jaynes in _The Origin of Consciousness in the Breakdown 
of the Bicameral Mind_ where he conceives of thought as primarily 
metaphor construction). But I have never been successful at enforcing 
linguistic rectitude by fiat. Rather, students do not seem to be able 
to consistently use precise terminology until after they have 
explicitly discovered the need to make precise discriminations. For 
example, I usually have students use 9.8 for everything having to do 
with gravity, and in fact calling it gravity, until they try to use 
it for a gravitational force (conveniently omitting the units)
and get a patently silly answer. I do consistently refer to it as an 
acceleration and insist that they do so as well but they are not 
consistent about it until they discover the need for such 
discrimination themselves.

This is not a matter of introducing wrong concepts. Rather, it is a 
matter of how you get to introducing the right ones -- as a discovery 
or as a sermon. The former will stick, the latter generally does not.

Paul J. Camp                   "The Beauty of the Universe
Assistant Professor of Physics  consists not only of unity
Coastal Carolina University     in variety but also of 
Conway, SC   29528              variety in unity.
pjcamp@csd1.coastal.edu             --Umberto Eco
pjcamp@postoffice.worldnet.att.net    The Name of the Rose
(803)349-2227                         
fax: (803)349-2926