[From Richard Thurman (950315.0840)]
Joel J. & Bill P. (various posts concerning memory & 'encodingism')
Joel and Bill, I just wanted you to know that I have not ignored your
posts on these points (about three weeks ago). In fact I sent several
posts in reply but my e-mail service was severely disrupted and none
of them seemed to make it to CSG-L. (Anybody else out there despise
Banyon as much as I am beginning to?) Then I was in England for a week
(not fun, just work) so that now the trail is cold.
When I returned there were well over 100 posts from CSG-L alone to catch
up with. Amazing!
Joel, I sent over to the ASU (Arizona State) library to retrieve Bickhard
(1992), Perkinson (1984), and Petrie (1981). While they show up as not
being checked out, they are not to be found in the stacks. Evidently
someone has them hidden away for their personal use. This is unfortunate
because I am very curious to see how they fit in with PCT, learning and
education.
···
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Gary Cziko (950303.1620)
Annual Meeting of the American Educational Research Association
April 18-22, 1995; San Francisco, CA
Thursday, April 20, 8:15 to 10:15; Hilton, Parlor 1, Ballroom Level
25.11 Perceptual Control Theory: A Postcognitive Theory of Behavior--A
Demonstration and Workshop-Discussion Strand (AERA-Demonstration)
This is great news! I plan on being there and telling every
colleague I can think of to be there also. Most of my colleagues are
in the field of instructional technology and are very tired of the
Gagne'-Briggs kind of approach to instruction. Perhaps this
will provide an avenue for them to start thinking about a
"postcognitive" theory of instructional design.
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Bill Powers (950313.1540 MST)
The real payoff of negative feedback comes when there are complex
relationships between input and output. By feeding back from the final
result to intermediate stages of the forward process, we can simply
eliminate the complex computations that otherwise would have to be done.
The feedback accomplishes with a few simple connections what would
otherwise have to be done by computing the inverses of all the forward
functions that lie between input and the final result. That's how the
Little Man arm model can stabilize a 3-df arm in real time using only
about 30 or 40 lines of code, where the equivalent open-loop performance
using inverse kinematics and inverse dynamics would take a Cray computer
to run as fast, and would use hundreds of lines of code.
I was in England at a NATO workshop on the uses of virtual reality in
educational technology. While there I talked with several companies
about the possibility of using PCT as a basis for building artificial
(virtual) actors within these environments. Some companies are now
using inverse kinematics for getting their virtual actors to move about.
I tried to explain the problems of computing the inverses of forward
dynamics as a way of providing movement (with some little success). At
least one company was (sort of) interested in looking at PCT as a way of
providing a less computationally severe approach to the problem (perhaps
they were just being courteous -- after all they see me as a customer of
their products). After describing the Little Man demo and telling them
that it took less then 100 lines of code to get a stable arm-shoulder
model, I took the liberty of asking them if they would be interested in
loaning some equipment to develop a fuller model. They indicated they
were willing to entertain the idea.
This may be an avenue worth exploring. I have tried for about a year to
use the resources at my lab put the Little Man into a virtual
environment, but so far have not been able to make it happen. There are
just too many constraints here. (Mostly because I am not a programmer and
I can't do the coding myself.)
Bill, (or anyone else) if I can talk them into loaning out some VR
equipment (a UNIX based CPU and peripherals, some development software
and 'C' library routines) would you like create a virtual actor? It may
be an opportunity to get PCT out there as a 'standard' for creating
virtual entities.
This is all very tentative but I thought I would at least try to see if the
VR community and the PCT community have an opportunity to help each other.
Is it worth pursuing, or do your interests head in another direction?
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Gary Cziko (950311.1602 GMT)
For those of you with access to the World-Wide Web, I recommend that you
take a look at the hypermedia "book" _Engines for Learning_ by Roger Schank
of the Institute for the Learning Sciences at Northwestern University. It
can be found at:
http://www.ils.nwu.edu/~e_for_e/index.html
I dream of having materials organized this way about PCT. But not only is
the organization of this book impressive, it makes many arguments for
revising education that fit very nicely into PCT.
Gary, this is a great source! Thanks for posting it. I can see why you
would want to use it as a model for creating a WWW page for PCT.
By way of furthering my understanding of PCT and education what do you
believe are the "arguments for revising education that fit nicely into
PCT?"
Rich
QUIT