[From Bill Powers (920917.0900)]
Greg Williams (920917) --
If anyone is trying to make an ideological point here, it is you, not
me. For the past several posts, I've been answering your
counterproposals by reasoning as strictly as I could from the model.
I've been pointing out that you've made mistakes in applying the
model, that you're shifting the definitions of your terms to suit your
immediate objectives, and that control theory itself, regardless of
ideology, doesn't agree with your claims. None of this has succeeded
in shaking your position that the world is full of people purposively
and successfully controlling the behavior of other people. You seem to
want me to change the model so its conclusions will agree with your
interpretations.
I've repeatedly pointed out things you say about what a control system
would do are not what it would do, according to the theory. You never
come back and say that my analysis was wrong, and that the model would
behave as you said, not as I said. Instead you just look for a
different way of making your point, as though the strict rightness or
wrongness of a particular argument involving the model is of no
account. This gives the impression that protecting the conclusion from
disturbance is more important than any particular argument by which
this is done.
Taking a tip from my own model, I must admit defeat. I can see what
you're controlling for, and I can see that arguments based on the
model are not going to affect the outcome. Your world is full of
people successfully controlling the behavior of other people, and will
remain that way. I can't convince you that this is a
misinterpretation.
I don't know where to go from here. Answers to all your points are
boiling around in my head, but I guess I've stopped believing that
they make any sense to you.
ยทยทยท
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eric harnden (920917.0930) --
RE: Stella.
Thanks for all the answers. It does seem that using Stella either for
interactive experimenting or for matching models to real behavior
would be pretty difficult, perhaps impossible. About the best that
could be done would be to read out tables of results from Stella, and
write another program to compare them with experimental results. How
do the System Dynamics people handle the comparison of model behavior
obtained with Stella with real-system behavior?
Would you mind posting once more the name of the guy who's in charge
of Stella, and if you have it, an address? I think I'll write to see
if he has any interest in PCT. If he could be persuaded to include
just user-written functions, a lot of needs would be met.
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Best,
Bill P.