[comp.object] Sample OO Expert Systems?

obrien@aerospace.aero.org (Mike O'Brien) (03/22/90)

We're looking for samples of an expert system that's truly object-oriented,
whatever that means.  One thing it does mean is that it's not just another
set of rules.  We know about Humble and that doesn't count: though it's
written in Smalltalk it's basically just another expert system shell like
many others, and things don't really get object-oriented till you go outside
it to write special Smalltalk code.

What IS an OO expert system?  Any takers?
--
Mike O'Brien
obrien@aerospace.aero.org

noren@dinl.uucp (Charles Noren) (03/23/90)

In article <69312@aerospace.AERO.ORG> obrien@aerospace.aero.org (Mike O'Brien) writes:
>We're looking for samples of an expert system that's truly object-oriented,
>       [stuff deleted].
>What IS an OO expert system?  Any takers?

One expert system I've played with is G2 by Gensym
(Cambridge, MA (617)547-9606).  It has some OO features,
but is not a OO expert system.  Some of its features:

  1.  A graphics oriented environment where objects usually
      have a graphics icon representation.  The language
      provides primatives that allow the icons to move,
      rotate, change color, be created or destroyed.

  2.  A "class" definition scheme that specifies [single] inheritence,
      instance attributes of the class, icon graphic description,
      and categories this class definition can be placed in.

  3.  A rule system that can manipulate object instances, classes,
      and attributes.  The rules can be activated by forward and
      backward chaining, by time, and any specified changes to
      existing objects.

  4.  A procedural language that can be called from the rules.

  5.  An optional interface to C.

  6.  A simulation engine.

Objects, definitions, etc., are developed one "workspaces", which
can be nested in a hypercard fashion.  G2 does not support the
concept of methods tied to classes and objects.

G2 is a nice prototyping tool.  It has a context sensitive editor
and its rule syntax is "english-oriented".  We have used it to
develop network management applications.

Now that I've been converted into the OO religion :-) I wish there
were more OO features in G2.  We have found that it provides
enough interesting features to rapidly put together an application
with developers who don't have experience in Lisp or other AI
languages.
-- 
Chuck Noren
NET:     ncar!dinl!noren
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