A Few Thoughts on an Ontology as a Self Organizing System

["Roger L. Costello" <costello@mitre.org>]

Hi Folks,

This is a continuation of the discussion that we had last week on
complex systems.  I have a couple of somewhat fuzzy ideas that I would
like to throw out.  My objective is to stimulate the flow of ideas, and
perhaps bring clarity to my ideas. 

Mike Champion made an interesting statement last week while discussing
semantics:

> But how about the messy real world most of us must
> operate in, where there is an intent to deceive
> (spammers, virus writers, software companies with
> patents on common sense, politicians starting wars [or
> questioning the definition of "is"], ad nauseum)? How
> about in pop culture contexts where meanings of words
> are changed literally for the fun of it?

That got me to thinking.  Suppose that we define the collection of all
XML tags that are used within a domain as a "system".  Let me refer to
each individual tag as a "part" of the system.  The system is
dynamically expanding and shrinking, i.e., parts (tags) are being
introduced/withdrawn all the time.  There are both fixed and changing
interactions in the system, i.e., some parent/child, sibling, semantic
relationships are fixed, others change.

What we have is a complex system.  I could continue on with this
description and talk about system properties, emergent properties,
attractors, etc.  However, since the topic is semantics, I would like to
focus on the use of ontologies in such a system.

Ontology languages such as RDF Schema and OWL provide the ability to
*statically* capture semantic relationships.  However, as Mike points
out, semantics is a continually evolving thing.  As a system evolves, so
must the ontology evolve.  In fact, an ontology must be part of the
system.

"The essence of self-organization is that system structure often appears
without explicit pressure or involvement from outside the system."[1] 
To manage evolving semantics a system must self-organize as semantics
evolve.  In other words, an ontology must be a constantly evolving
entity.

How can we create an ontology that evolves?  Here is a thought: express
semantic relationships in an XSLT document!  An XSLT stylesheet has an
interesting property of being able to output a modified version of
itself, i.e., the output of the stylesheet is another, modified,
stylesheet.  The output stylesheet may contain template rules that have
been modified to reflect changing semantics, and additional template
rules that contain new semantic relationships.

Honestly, I am not sure how one would express semantic relationships in
a stylesheet. For example, how would you express that a SLR is a type of
Camera, or aperture is synonymous with f-stop?

Well, that's it.  As you can see my ideas are rather fuzzy, but perhaps
they will stimulate your thoughts.  /Roger

[1] Self-Organizing Systems FAQ for Usenet newsgroup
comp.theory.self-org-sys