models in the wild (was Re: [Swarm-Modelling] Re: [Swarm-Support] Repast vs. Swarm)

[gepr]

Steve Railsback writes:
 > One key to making ABS more acceptable as science is developing common, 
 > widely used modeling concepts, terms, frameworks, and tools. To me one 
 > of the coolest things about Swarm is that the project started off with 
 > the goal of meeting these needs; and has succeeded to some extent.

Exactly.  Modeling and simulation are as useful as any other tool.  As
Marcus pointed out, advocating the use of ABM (especially as "the
only" or "the best" way to do something) is about as silly as
advocating the use of the beaker in chemistry. [grin] It's a tool that
you either use or don't.  If you use it, have a good reason.  If you
don't use it, have a good reason.

The real issues lie in the _methods_.  How do you use simulation?  How
do you use your models?  Are your models well specified?  (In the same
way your experimental devices either have spec sheets that are
believable or they don't.)

But, as I've said before, the best way to move into discussions about
methods and materials is to get away from the concept of "simulation".
Simulation is all about being able to mimic some phenomenon without
acurately implementing the machine that generates that phenomenon.
That requirement is akin to the Turing test for intelligent machines
and presents us with all sorts of time-wasting arguments.

The direction to move into is to create computational devices that you
experiment with/on.  You have to treat these _devices_ like they are
material objects to be used in an experiment.  And that means abandoning
the idea of mimicking things.

(Note: There is a broader sense of the word "simulation" that still
applies here.  It is that of man- and hardware-in-the-loop simulation
or those activities that might be more appropriately termed
"exercises" or role-playing.  Those "simulations" push the boundaries
towards that of building analogs -- chemical, physical, electrical,
etc. -- such that experiments can be performed on multiple analogs and
the outcomes compared.  I'm suggesting we move further toward this
sense of the word "simulation," which is less focused on mimicry and
more focused on the methods involved in carrying out experiments over
those systems.)

I believe that agent-based _systems_ (not "models") are an ideal way
to approach this type of "models gone wild" (sorry, I couldn't resist
;-) development of _method_.  It's much more natural and intuitive to
think of ABSes as "analogs", with an existence apart from any
referent, than it is to think of systems of equations that way.

-- 
glen e. p. ropella              =><=                           Hail Eris!
H: 503.630.4505                              http://www.ropella.net/~gepr
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