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From: fostel@eos.ncsu.edu (Gary Fostel)
Newsgroups: comp.ai
Subject: Re: Emergent properties (was: What AI is exactly)
Message-ID: <1990Sep27.185805.21493@ncsuvx.ncsu.edu>
Date: 27 Sep 90 18:58:05 GMT
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Reply-To: fostel@eos.ncsu.edu (Gary Fostel)
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  Some of the recent posts have criticised the term "emergent property"
  as a euphamism for "we don't understand" and some have defended the
  term by examples of the application of the term and some have tried
  to justify the term as a valid one more abstractly.

  If I assemble a device from wheels, pedals, metal tubes and such,
  and it happens to become the most efficient transportation device
  around, is that an emergent property of the parts?  I doubt that
  defenders of the term would like it to be so.  But why not?  Probably
  because the transportation property was a goal of the design process
  that controlled the assembly.  Now suppose a Venusian engineer viewed
  this as a process of putting wheels, metals tubes, pedals, and an
  engineer, and a few tools, in a room.  These "parts" may well have
  an emergent property, from the perspective of the Venusian, since
  they had no expectation of a transportation function arising from
  the collection of parts.  (Yes the engineer is a part in this view.)
  I identify this as an emergent property because I believe it would
  satisfy most of the ad hoc definitions I have heard.  

  I do not expect most supporters of the "emergent property" term to
  like this use of the term.  They will not like it (I am guessing of
  course) becuase they will feel that they can identify the source
  of the property which has emerged ... but of course the Venusian,
  having utmost contempt for the large water based carbon compound in
  with the metal parts, will not be able to identify the source and
  the "emergence" is viewed from that creatures perspective.

  A second example: if you put large pine forrests, rabbits and foxes
  together in northern Canada, you will get a 10 year cycle of boom
  and bust in the populations of rabbits, foxes and young pine trees.
  (Rabbits LOVE to eat pine needles, far more than carrots.)  Is this
  pattern an emergent property?  From the perspective of a naive and
  innumerate individual, the answer is certainly yes.  The cycle is
  there, it was not predicable (by them) and it is not easy to 
  identify the source in myopic analysis of rabbits, foxes, or pines.
  From the perspective of an ecologist or someone versed in simple
  dynamical systems theory, it is not an emergent property.  It can
  be predicted, modeled, and well explained, based on properties of
  the constituent elements, e.g. kilocalories needed, supplied, 
  gestation period, etc.

  Again, I would expect advocates of the "emergent property" term to
  be somewhat bothered by this situation, but I believe it is because
  they will tend to automatically associate with the technically
  astute view of the dynamics.  Two hundred years ago, ecologists
  knew it happenned but did not understand at all why.

  But, it was not called "an emergent property of rabbits, foxes and
  pines".  It was simply an unexplained experimental observation.  That
  does not have nearly the same gloss, but it is more accurate.  By
  saying that X is an emergent property of {A,B,C...} and by providing
  some sort of definition for the term "emergent" an unsubstantiated
  conclusion has been reached.  A few people seem to make this part
  explicit in the use of the term, directly or indirectly saying the
  explanation WILL NOT come from reductionist methods, not simply that
  it HAS NOT come from that source.  Certainly, in the case of neural
  systems (real or synthetic) it is not known that a suitable means
  of reductionist explanation will not be found.  Just that it has not
  been found.

  (So-called "chaotic systems" are an interesting counter point, since
  there is some analytic evididence that there are classes of systems
  for which it is not possible to predict specific behavior, based on
  ANY measurement of the system.  But in these cases, it IS often
  possible to characterize the sorts of behavior that the system is
  capable of.  I take it that emergent properties deal in the currency
  of behavior characterizations, not specific predictions, so the
  behavior of a chaotic system is not an "emergent property".)

  People studying intelligent systems seem to operate as if they already
  know what the suitable "atoms" of the systems are.  Since they
  are unable to explain the observations based on properties deduced
  from these atoms, they reach for terms such as "emergent properties"
  rather than doing good science and looking to reformulate the basic
  hypothosis in new ways.  Hiding behind a pseudo-science of "emergent
  properties" will probably delay the real struggle: to find more
  suitable analytic tacts and more suitable atoms to form the 
  foundation of a "proper" scientific explanation.

  I doubt advocates of "emergent properties" will like that either.
----gary----