Re: Formal explanations vs. pathways of understanding (was: momentum before force

[dykstrad@varney.idbsu.edu (Dewey Dykstra, Jr.)]

To all:

Leigh Palmer said:

> Dewey's idea of considering the historical path taken towards physical
> enlightenment as a pedagogical strategy is an interesting one. There
> are cases where it would not be advisable to do so, however. Conspicuous
> among those cases is Kepler's approach to his laws of planetary motion*.
> Kepler is said to have documented all his blind alleys, so that the path
> could be followed if one wanted to. He even considered and discarded the
> ellipse before returning to it and accepting it for his first law. While
> it might be very interesting to follow his path, it would be inefficient
> to do so, I'm afraid.

To suggest that we lead students up all the blind alleys is not what I was
advocating.  It is possible to discern the _issues_ in which the scientists
in history were engaged and to find ways of getting students engaged in
similar ones.  Having the students retrace or for us to recount the history
without engaging students in the issues is a waste of time and no more
productive than what we are doing on the average today.  If the _students_
are not engaging and comparing _their_ ideas with the phenomena then little
change in _their_ ideas should be expected, but isn't that change in
_their_ ideas the point?  (If not, then maybe physics education is _not_
for the purpose of helping students develop their understanding of the
world of physical phenomena, but for some other purpose instead.)

> It must also be considered that perhaps Newton et al. were more able
> than the run of the mill among our students. Their minds were, perhaps,
> better prepared to follow those paths than our students' minds will be.

A good excuse which as covered the failure of physics teaching for most
students for many decades and probably will for many more.

> Still, each of us can easily recall sitting through a well delivered,
> sparklingly lucid lecture in which a phenomenon was elegantly presented
> and explained in terms which would make the listener wonder why it all
> was not evident to Adam/Eve, only to leave and be utterly incapable of
> reproducing the argument. Even a perfectly sound, rigorous presentation
> can be too slick useful for teaching purposes.
>
> I, too, see great value in presenting more of the historical development
> of physics in our courses. It is difficult to do so when we try to pack
> too much in, but it is worth doing in my view because it is interesting,
> and we often lose the interest of students with unleavened physics. The
> additional value, which I will not minimize, is that if it is taught with
> the proper degree of respect for our intellectual ancestors, students may
> develop that respect themselves, something I think very desirable.

So, I am _not_ advocating presenting the historical development, but
getting students to engage in similar (the same) issues that people
previous to them took up and found 'led them somewhere' useful.

Now this may not be exactly what Leigh meant, but if 'respect for our
intellectual ancestors' is manifest by statements such as:

> ...perhaps Newton et al. were more able
> than the run of the mill among our students. Their minds were, perhaps,
> better prepared to follow those paths than our students' minds will be.

then I see no redeeming value in it.  I doubt that 'our intellectual
ancestors' would feel deserving of such worship (except maybe for Newton)
and most would decry such when they consider what this says about the
attitude we are expressing about students.  If this is what we believe,
then I guess 'we' have no problem leaving things as they are.  We have a
perfect excuse to do so, because we have such poor material with which to
work.


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Dewey I. Dykstra, Jr.                   Phone: (208)385-3105
Professor of Physics                    Dept:  (208)385-3775
Department of Physics/SN318             Fax: (208)385-4330
Boise State University                  dykstrad@varney.idbsu.edu
1910 University Drive                   Boise Highlanders
Boise, ID 83725-1570                       novice piper
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