System Dynamics [fwd]

Francis Heylighen (fheyligh@VNET3.VUB.AC.BE)
Tue, 12 Dec 1995 15:08:59 +0100


Date: Tue, 12 Dec 1995 08:18:54 +0001 (EST)
From: Arlen Wolpert <awolpert@world.std.com>
Subject: System Dynamics
To: fheyligh@vnet3.vub.ac.be
Cc: G.P.Richardson@Albany.edu

Dear Prof. Heylighen:

I am a system dynamicist (Forrester-style). I was heartened by
your web page at <http://134.184.35.101/SYSTHEOR.html>
and some of your other web pages in which you indicate you
and your associates are attempting to integrate the various
system theories, including Forrester's system dynamics. However
my recent experience with EMCSR-96 indicates there are problems
in doing this and the integration will take a long time. Here is my
experience:

I submitted a paper to EMCSR-96 in which I use system dynamics
to model mental processes. (To get an idea of my work see
<http://world.std.com/~awolpert>.) It was rejected based (not
on its controversial nature but)on the following reason, as stated
in the attachment to Dr. Trappl's letter:

"The author applied the Forrester model used in industrial dynamics
to understand mental processes. The prerequisites for applying
these models are that the variables are measurable preferably on
a ratio scale, at least on an interval scale. These conditions are
definitely not fulfilled by Mr. Wolpert's mental variables. Therefore,
the model is falsely applied."

However, if you will access a brief synopsis of System Dynamics at
<http://sysdyn.mit.edu/whatsd.html> you will note Forrester's
5th principle:
"Quantification of unmeasured but important concepts and relationships."

George P. Richardson, the former editor of the System Dynamics Review,
has written a book called "Feedback Thought in Social Science and
Systems Theory". His book tries to do the same noble task that
you and your associates are attempting to do: Integrate the various theories.

I showed the above rejection from EMCSR-96 to Richardson. He
said he will attempt to open up a dialogue (not on my work because
it is too controversial but)on the general subject of the misunderstanding
of SD among system theorists. He will probably also bring up for discussion
the subject of soft or unmeasurable variables. It would be a pleasure
if you and your associates joined the discussion. If you care to do so,
email a message to <majordomo@world.std.com> containing the
following text in the body (the subject line is ignored):

subscribe system-dynamics
end

Forrester has been an active contributor to these discussions.

Regards,

Arlen Wolpert
Independent Scholar
411 Franklin Street, Apt. 1008
Cambridge, MA 02139 USA
Telephone: (617)547-6994
email: awolpert@world.std.com