At 12:10 PM 10/17/00 +0100, you wrote:
>I wonder if Keith's posting indicates that at least some arguments have been
>(perhaps not surprisingly) at cross purposes.

Yes, Scott, there were many postings of yours which I thought were not
directly responding to the points I had made in my prior posting.  The
points that I made in my postings, including the one that started off the
whole thing (10/3) are those that I just stated in my summary of the main
themes.  I don't think that you ever provided a counter-argument to my
claims in themes (1) and (2); although you were frequently dismissive of
the relevance of sociology, your discussions of "validation" were not
arguments against the relevance of sociology, nor were they arguments
against the potential necessity of explicitly modelling social entities.  I
always agreed with you in your insistence that MABS be validated, but then
I claimed that this could only be done by establishing a more direct
relationship with sociology.

Of course I agree with you that themes (1) and (2) are indeed issues
related to validation of models.  I never disagreed with this.  And I agree
that the question of what constitutes validation is closely related to the
question of "What is the relevance of sociology."  One way that sociology
is relevant is that it is where MABS goes to validate its models; as I
said, it is our "source discipline".  Your postings implied that there was
some other way to validate MABS models, but you never said what that might
be.  Consequently, our discussion has not been one about "all of the ways
that MABS could be validated," but instead it has specifically been a
discussion of "how sociology can be used to validate MABS models."

>Just to be clear: my concern is that representational social simulation
should be
>validated with respect to real, target social systems and their
components.  When
>there are well validated social or other theories that support mechanism
and/or
>agent designs implemented as a social simulation model, then the
confidence we can
>have in that model will be strengthened by verifying the model or its
components
>with respect to such a theory.  I habitually employ agent designs taken from
>cognitive and social psychological relations experimentally and
observationally
>validated by cognitive scientists and social psychologists.  

It is telling that you have left "sociology" out of your list.  This is why
theme (2) is one of the UBER-themes of our disagreement.  The two
disciplines that you draw on are NOT sociological; they are theories about
INDIVIDUALS.  If you are interested in developing a good model of the
agent, then of course you should draw on empirical scientific disciplines
that study agents; and you should go to the "intelligent agents"
conference.  But if you want to develop a good model of a social system--as
MABS hopes to do--then you need to draw on the scientific discipline that
studies social systems: namely, sociology.  


This brings me to what I think is a mis-characterization of my proposed
second theme:

>> (2) is it ever appropriate for a MABS to explicitly model any entities
>> other than individual agents?  If so, when is it, and how do we determine
>> when; e.g., by reference to sociological data or theory, or through our own
>> engineering concerns?  Phrased this way, this theme is in part a subtheme
>> of (1).
>
>This indicates to me that Keith (by no means alone) has been concerned
primarily
>with sociology while the practicing MAS modellers in this discussion have
been
>concerned primarily with agent and mechanism design.

I don't see how you could interpret theme (2) as a "primarily sociological"
theme.  It is couched explicitly in terms of practical issues of modelling.
 All of my prior postings on this point have been quite explicit about the
implications for modelling.  Your above statement about how you draw on
social psychology, and my response about how you have neglected sociology,
again restates why this issue is directly relevant to issues of MABS
modelling.  

>Do these alternative specifications of the questions help to identify the
>differences between us?

I think we are moving forward but we don't have intersubjectivity yet.  In
our newsgroup discussion, I have agreed with everything you have said about
validation being important, but you have disagreed with most of what I have
said about themes 1 and 2: the role of sociology in validation, and the
types of entities that MABS should be modelling.  That's why I think themes
1 and 2 are the primary themes of the debate.  Let me know whether these
responses have clarified anything for you.  

R. Keith Sawyer
Assistant Professor
Program in Social Thought and Analysis
Washington University
Campus Box 1183
St. Louis, MO  63130
314-935-8724



http://www.artsci.wustl.edu/~ksawyer