Next: Summary and the way Up: Knowledge Representation Previous: Procedural Knowledge

Issue in Knowledge Representation

Below are listed issues that should be raised when using a knowledge representation technique:

Important Attributes
-- Are there any attributes that occur in many different types of problem?

There are two instance and isa and each is important because each supports property inheritance.

Relationships
-- What about the relationship between the attributes of an object, such as, inverses, existence, techniques for reasoning about values and single valued attributes. We can consider an example of an inverse in

band(John Zorn,Naked City)

This can be treated as John Zorn plays in the band Naked City or John Zorn's band is Naked City.

Another representation is band = Naked City

band-members = John Zorn, Bill Frissell, Fred Frith, Joey Barron,

Granularity
-- At what level should the knowledge be represented and what are the primitives. Choosing the Granularity of Representation Primitives are fundamental concepts such as holding, seeing, playing and as English is a very rich language with over half a million words it is clear we will find difficulty in deciding upon which words to choose as our primitives in a series of situations.

If Tom feeds a dog then it could become:

feeds(tom, dog)

If Tom gives the dog a bone like:

gives(tom, dog,bone) Are these the same?

In any sense does giving an object food constitute feeding?

If give(x, food) feed(x) then we are making progress.

But we need to add certain inferential rules.

In the famous program on relationships Louise is Bill's cousin How do we represent this? louise = daughter (brother or sister (father or mother( bill))) Suppose it is Chris then we do not know if it is Chris as a male or female and then son applies as well.

Clearly the separate levels of understanding require different levels of primitives and these need many rules to link together apparently similar primitives.

Obviously there is a potential storage problem and the underlying question must be what level of comprehension is needed.

Next: Summary and the way Up: Knowledge Representation Previous: Procedural Knowledge

dave@cs.cf.ac.uk