Re: heat is a form of energy

["Daniel L. MacIsaac" <Dan.MacIsaac@NAU.EDU>]

> > ...what does "cognitively flawed" mean?  I believe you invented this term,
> > and I see a limb here...
>
> It denotes the property possessed by anything meant to instruct which
> would inhibit cognitio, (or be an obstruction to instruction!).
I have a problem with this position: if I could construct an ideal curriculum
taking an infinite amount of time I would teach every possible "misconception"
I could, and analyze it to explicate where these ideas were incomplete.  This
is actually how I have really learned my own physics as a teacher.

I believe Bill's point is that our current scientific knowledge state is
ALWAYS going to be incomplete; we will always find a better model to
describe the physical world.  Therefore we need to recognize that our current
models may always be corrected by a future model, and that's GOOD -- that's
how science progresses.  There is no golden "TRUTH" with a capital T, just
better approximations to nature.

> In this case I am asking how teaching Newtonian physics can lead to
> misconceptions which would hinder the student's later understanding
> of relativity. Teaching that "Heat is a form of energy" does have
> that effect on later instruction; it is cognitively flawed.

I believe that simpler models are often MORE cognitively appropriate for
instructional purposes than are more complex models of nature that may be
more mathematically correct but less intuitively approachable due to
student readiness.  I believe we should crawl, then walk and practise walking
before we jog, run & sprint or marathon.  We need to develop and use simpler
models, practise their use in appropriate circumstances, develop an
understanding of their limitations and move on to more complex models.

We need to SCAFFOLD understanding by studying light as particles, then
light as waves, then QED.  Electrons as billiard balls, then electrons
as clouds, then QM.  Newton's Laws, then add in SR, GR and QM.  You get
the idea; I'm not so interested in quibbling on specifics as seems to
be the case with heat.  Incomplete understandings are appropriate
intermediate goals for student understanding and for instruction.

The student's intellectual development can match the nature
of science here -- which is appropriate so the student can develop into
someone who understands scintific reasoning, and perhaps can stay
scientifically literate.

Even Feynman, who was infamous for wasting large chunks of his intellectual
life reinventing an understanding of all physics from first principals,
recognized and used early, incomplete models of physics in his teaching and
overtly noted this in his lectures.  See his comments on mirages, for
instance.  Most of our students will NEVER achieve the advanced mathematical
understandings of our cutting edge theories (nor will I personally) and a
simpler model that works for 99% of the phenomena in their lives is an
entirely appropriate goal.

Finally, I believe we have been entirely misconstruing misconceptions
research here by claiming we implant an idea that blocks later learning
of more advanced or different ideas. The word misconception itself is an
inappropriate direction to take, as it implies that once we know what the
student's misconception is, we can easily prescribe a cure by telling
them what our 'correct' conception is.  Several education (and physics
education) theorists such as Andy DiSessa (UC Berkeley) and Jim Minstrell
have written extensively on the fact that human beings do not learn entire
conceptual frameworks in one whole coherent piece; they learn small chunks
of information (not facts) as primitives (p-prims or facets) that are
cued to experiences.  These sub-conceptual primitives can be used to
construct conceptual understandings in immense frameworks, and these
primitives can be rearranged in different frameworks.

My idea is that we can't dispel "miconceptions" by never teaching BAD  or
incomplete information -- this can't be avoided.  However, we can teach
appropriate models for intermediate levels of understanding, and later
analyze these models with our students to reject or extend them into
deeper understanding.  It is not possible to graft "correct" or perfect
understanding of advanced models onto the minds of our students, nor is
this a realistic goal.

Finally, I like teaching earlier historic fluid models of heat and
electric charge flow; they are intelligent and useful models proposed
and successfully used by intelligent people (many are still in practical
use today in the engineering community in particular).  They work well
in their environment.  A critique of the limitations of these models
leads to deeper understandings and reflects the true nature of science
and the likelyhood that we will be revising our current understanding
of science in our own lifetimes.

I also like to point out that Martin Gardner in THE RING OF TRUTH talks
about heat as a very low mass caloric fluid moving from one object to another.
Gardner even points out that by Einstein's E=mc2 insight, hotter objects
are heavier.  Calor actually has some mass.

> You may back off that limb now.
>
> Leigh
With all due respect and great admiration for you Leigh, I don't think I'm
on the limb here.  I would hesitate at redefining terms that are well
researched and discussed in cognitive psychology, and applied to science
education research.  I always welcome the opportunity to learn more from
you and you have taught me much through our dialogues, but I profoundly
disagree with the heat debate and formulating my responses has only
added personal clarity to my disagreement.  I hope I communicated some
of my concerns as well as you have communicated yours.

Dan M

PS -- Believe it or not, I got a new chainsaw over the weekend for
cutting firewood.  Now I have to get a goalie mask to wear when
posting on PHYS-L :^).

Dan MacIsaac, Assistant Professor of Physics and Astronomy, Northern AZ Univ
danmac@nau.edu          http://purcell.phy.nau.edu         PHYS-L list owner