[From Bruce Gregory (2003.12.08.2023)]
Since many of you were doubtless not following the exchange on TRAFFIC
(perhaps you don't commute), let me call one very important point to
your attention. Lest I be accused of harboring some bias with regard to
the spreadsheet model, I will simply quote Rick:
"The spreadsheet is currently set up so that all perceptual
functions at all levels control independent degrees of freedom in the
array of perceptions (or sensory inputs) from the next lower level. If
you change the perceptual functions so that two systems at the same
level control the same perception (same degree of freedom) control by
the two systems and any higher level systems that use those systems as
the means of controlling their own perceptions is lost."
This is a very clear statement of the limitations of the current
spreadsheet model. This model is an example of what physicists call a
"toy model." A toy model is not intended to be realistic, but rather to
demonstrate principles that may apply to future more realistic models.
To the extent you are interested in modeling, Rick's forthright
statement might tell you something important. I leave that for you to
decide.
Bruce Gregory
"Everything that needs to be said has already been said. But since no
one was listening, everything must be said again."
Andre Gide
Bruce,
Contrary to my expectations you are finding yet more material in a vein
that I thought had been exausted.
I am in awe of this achievement. I can only say that this last post
has qualities.
Bill Williams
"All this is simple enough. It is so simple and [it] is
so obvious that is difficult to see it until it has
been pointed out, and after it has been pointed out
it seems to have been unnecessary to speak of it."
Observant readers will by this time have noticed that my post-text
epigram and Bruce's bear a anti-something or other relationship to
each other. Perhaps Bruce Nevin can supply us with the nominclature
by which we could refer to this relationship correctly.
···
-----Original Message-----
From: Control Systems Group Network (CSGnet) on behalf of Bruce Gregory
Sent: Mon 12/8/2003 7:23 PM
To: CSGNET@listserv.uiuc.edu
Subject: Rick's Spreadsheet Model
[From Bruce Gregory (2003.12.08.2023)]
Since many of you were doubtless not following the exchange on TRAFFIC
(perhaps you don't commute), let me call one very important point to
your attention. Lest I be accused of harboring some bias with regard to
the spreadsheet model, I will simply quote Rick:
"The spreadsheet is currently set up so that all perceptual
functions at all levels control independent degrees of freedom in the
array of perceptions (or sensory inputs) from the next lower level. If
you change the perceptual functions so that two systems at the same
level control the same perception (same degree of freedom) control by
the two systems and any higher level systems that use those systems as
the means of controlling their own perceptions is lost."
This is a very clear statement of the limitations of the current
spreadsheet model. This model is an example of what physicists call a
"toy model." A toy model is not intended to be realistic, but rather to
demonstrate principles that may apply to future more realistic models.
To the extent you are interested in modeling, Rick's forthright
statement might tell you something important. I leave that for you to
decide.
Bruce Gregory
"Everything that needs to be said has already been said. But since no
one was listening, everything must be said again."
Andre Gide