Print

---

One possible approach to at least detecting qualitative change ('real'
emergence) is good old fashioned cluster analysis.  This is suggested by
David Byrne in some of his work on complexity in the social sciences.  It
sort of goes against the grain to fall back on such an old-fashioned
'linear' tool, but cluster analysis is non-parametric and a reasonable way
to begin to explore the high-dimensional data-spaces generated by MAS.

OF course to get this sort of thing working well, better visualization and
analysis tools built in the modeling environments will be needed.

David


At 03:01 AM 4/10/2003 -0700, Carl Henning Reschke wrote:
>Hi
>
>as i see it the problem of increasing complexity
>through exponentially increasing reltions - that might
>or might not matter - is not the real problem in
>social simulation.
>
>The real problem is that of getting qualitative change
>into the model, and qualitative change in a fashion
>that goes beyond the phase transition type of change.
>
>This week there is short interview with Frank
>Schweitzer in c't a german computer magazine.
>He implicitly argues that one could get from
>quantitaive changes - the collective state a la pahse
>transition which emerged form the interactions  among
>agents - via co-evolution to qualitative change, i.e.
>"second-order emergence" (I am not quite sure whether
>he really means the same as von Foerster).
>He concludes - as far as he knows - that nobody has
>managed to reach self-organisation models of
>hierarchical social structures.
>
>a) Is he right?
>b) why?
>
>And now comes some marketing ;) theres an article of
>mine in JASSS 4/4/8 from 2001 that touches upon some
>of the problems.
>
>There is also the work of R.A. Watson at Brandeis how
>is working on a computational implementation.
>
>The basic problem is that of emergence and how it is
>possibly brought about by compartmentalization - that
>is actually sth that Herber Spencer - despite other
>misgivings - got right in his trial to identify
>evolutionary principles in/from biology and sociology.
>
>Similarly Margulis theory of increasing complexity in
>cell-evolution works with fusion and
>compartmentalization.
>Szathmary and Maynard Smith also present some
>mechanisms to overcome this problem in their 1995
>article (Nature it was I think).
>
>Therefore the way to succes might be to defocus from
>interaction and get the fusion/compartmentalization
>into the model since it could deliver the system
>transition that seems necessary for qualitative change
>/ emergence. This is not necessarily a problem of
>computing power and computability, but of model /
>system structure.
>
>Comments? Am I right or did i oversee sth?
>
>Best,
>Carl Henning Reschke
>
>--- "Bayer, Steffen" <[log in to unmask]> wrote:
> > Hi,
> >
> > as far as I can see Loet's argument about the
> > enormous increase in the
> > computational space for social systems is even
> > stronger than he makes it.
> >
> > If we allowed persons to have multiple relations,
> > there could be many more
> > than 10^10 configurations of relations between 10
> > persons.
> >
> > If I am not mistaken there would be (2^9)^10 = 2^90
> > configurations if
> > relations could be uni-directional and (2^9 + 2^8 +
> > 2^7 + 2^6 + 2^5 + 2^4 +
> > 2^3 + 2^2 + 2^1 = 2^45) if relations were
> > bi-directional.
> >
> > Steffen
> >
> >
> > Dr Steffen Bayer
> > Innovation Studies Centre
> > The Business School
> > Imperial College London
> > South Kensington Campus
> > London, SW7 2AZ, UK
> >
> > ph.: +44-(0)20 759 45935
> > fax: +44-(0)20 7823 7685
> > office: Rm 101, Civil Engineering bldg
> > http://www.imperial.ac.uk/business/innovation
> >
> >
> > -----Original Message-----
> > From: Loet Leydesdorff [mailto:[log in to unmask]]
> > Sent: 08 April 2003 18:37
> > To: [log in to unmask]
> > Subject: Re: computability ... Re: Bit-flipping
> > model of culture
> >
> > Dear Andreas and colleagues,
> >
> > I thought that non-computability is particularly
> > relevant to social
> > systems because the N of cases is part of the
> > exponent. The
> > computational space then rapidly explodes.
> >
> > For example, if one throws two dice there are 6^2
> > possibilities. If one
> > throws three dice, there are 6^3 possibilities, etc.
> > In general: 6^N,
> > where N is the number of dice.
> >
> > Analogously: If we have a group of 10 persons who
> > can all maintain
> > relations with each other, this system has 10^10
> > possible states if each
> > configuration of relations is counted as one
> > possible state. The
> > specification of mechanisms (hypotheses) selects on
> > this phase space and
> > makes the system computable.
> >
> > With kind regards,
> >
> >
> > Loet
> >   _____
> >
> > Loet Leydesdorff
> > Science & Technology Dynamics, University of
> > Amsterdam
> > [log in to unmask] ; http://www.leydesdorff.net/
> >
> >
> > > -----Original Message-----
> > > From: News and discussion about computer
> > simulation in the
> > > social sciences [mailto:[log in to unmask]] On
> > Behalf Of
> > > Andreas Schamanek
> > > Sent: Sunday, April 06, 2003 12:31 AM
> > > To: [log in to unmask]
> > > Subject: computability ... Re: Bit-flipping model
> > of culture
> > >
> > >
> > > Hi SIMSOC,
> > >
> > > On Tue, 1 Apr 2003, Alan Penn wrote:
> > >
> > > > This brings a question to mind: are there any
> > qualitative
> > > properties
> > > > of systems that are provably _not_ representable
> > in terms of bits?
> > > >
> > > > The theory of computation says that anything
> > computable can be
> > > > computed using a finite state machine (if I
> > understand it
> > > right) so I
> > > > suppose such properties - if they exist - must
> > not be
> > > computable. If
> > > > so what are they, and are they socially
> > interesting?
> > >
> > > From a social sciences' point of view (and quite
> > some more),
> > > I'd say that I do not like the notion of
> > 'computability'. Is
> > > there a property that is not represented in any
> > way? Is there
> > > a property that cannot be represented in some way?
> > Every
> > > computation is some form of representation (that
> > we generally
> > > call model). It depends solely on yourself (and
> > your
> > > colleagues) whether a property is computable or
> > not.
> > >
> > > Of course, the notion of 'representation' is also
> > a
> > > representation. But, that's a different story.
> > >
> > > Another story, since we have already discussed
> > lots of chaos
> > > theory, here, goes like this: As most of you know,
> > one of the
> > > properties of a deterministic chaotic time series
> > is the fact
> > > that values do not repeat. No matter how often you
> > iterate,
> > > e.g., the logistic equation
> > >
> > >   X(n+1) = 4 * X(n) * ( 1- X(n) ) ;  X(0) out of [
> > 0 ... 1 ]
> > >
> > > there will never be a value of X(n) that equals
> > any other
> > > X(m) except for m = n.
> > >
> > > A computer is only a finite state machine. It can
> > compute
> > > everything, but only given enough time and enough
> > finite
> > > states :) Our everyday computers are _very_ finite
> > state
> > > machines. So, if you compute the logistic equation
> > with a
> > > computer (using some computer language, say
> > FORTRAN or C),
> > > you will observe that already after only a few
> > iterations of
> > > the logistic equation you will get a X(n) that you
> > have seen
> > > before. Once you have found this X(n), say after p
> > > iterations, every X(m+p) will equal X(m) for m =
> > n, n+1, n+2,
> > > ... You have found a cycle, a period of length p.
> > (p, by the
> > > way, is astonishingly small: often only a few
> > thousand
> > > iterations if you declare/define X as a single
> > precision variable).
> > >
> > > So, here is a property that is (generally) not
> > computable:
> > > Deterministic chaos.
> > >
> > > Besides non-periodicity there is also the Lyapunov
> > exponent
> > > which shall be above 1 for chaotic time series.
> > The Lyapunov
> > > exponent, by the way, is a measure for how much or
> > how fast 2
> > > time series that describe the same system will
> > nevertheless
> > > diverge if computed with slightly different
> > values.
> > >
> > > The strange part of this story is that when you
> > compute the
> > > Lyapunov exponent for a time series generated by a
> > > computation of the logistic equation, i.e, a
> > periodic time
> > > series, you still get values above 1.
> > >
> > > Does that mean that when we look at computed
> > non-computable
> > > properties by means of computation that we see the
> > world just
> > > like it is?
> > >
> > >
> > >
> >
>=== message truncated ===
>
>
>__________________________________________________
>Do you Yahoo!?
>Yahoo! Tax Center - File online, calculators, forms, and more
>http://tax.yahoo.com

--------------------------------------
Penn State Geography - GeoVISTA Center
University Park, PA 16802, USA