general concepts

[wschoppe at mason2.gmu.edu]

In my development of a generic ACT-R model that enacts GOMS models, I
encountered the following problem which seems to be general enough to be
discussed here.
It is about the relation between specific instances and general concepts
as illustrated by the following chunks:

(specific-instance
   isa state-of-the-world
   slot1 A
   slot2 B
   slot3 C
)

(general-concept
   isa state-of-the-world
   slot1 A
   slot2 any-chunk
   slot3 any-chunk
)

"any-chunk" stands for the notion that any chunk should math here.
What I would like to model is that the general concept matches when the
specific instance is on the goal stack. The following example of a
production that tries to retrieve a selection rule may illustrate that
(for several reasons, I would like to represent the selection rules
declaratively).

(p retrieve-selection-rule
  =goal>
     isa generic-goal
     world =world      ;=world is bound to specific-instance
     method nil
     ...
  =s-rule>
     isa selection-rule
     world =world      ;suppose there is a selection rule with
general-concept in its world slot
     method =method
 ==>
  =goal>
     method =method
     ...
)

One solution to the problem would be the use of partial matching and
setting high similarities between specific instances and general
concepts. But because specific instances are created during runtime,
this would be quite a hack.
Another thing I would like to have in that model is that
specific-instance spreads activation to general-concept, because it
seems reasonable that seeing a specific instance in the environment
should enhance the retrieval of the corresponding general concept.
Again, that could be accomplished by writing a function that sets IAs
between newly created state-of-the-world chunks and the corresponding
general concepts.
All that could be avoided if there was a special chunk "any-chunk" which
literally matched any chunk.
Generally, the described problem should always occur in models of object
hierarchies.
Has anybody thought about similar things, come up with a solution, or
even thought about including such a  feature in the architecture?

Wolfgang


P.S.
Another example for the use of "any-chunk" is the concept of
"multiplication with zero":

(mult-zero
   isa ...
   fact1 0
   fact2 any-chunk
   prod 0
)