Hi, I''m not a game designer but i am studying AI as a psychology module, and one of the aspects i have the study are the 2 knowledge representation methods above. I was wondering what their strenghts and weaknesses are? Thanks

I can tell you that semantic networks are only good if you need to store relationships between objects. Predicate calculus sentences are better for rules and storage.

is it possible to combine the 2? If so then why isn''t it merged into a new type of Knowledge Representation? And if not - why not?

Take a look at the work done on NAG (Nice Argument Generator). NAG combines semantic networks and Bayesian networks... so in that sense, it''s not a combination of the semantic network/production system you were looking for... but it''s similar... and BNs don''t have the same sorts of problems that productions systems have (but they do have their problems). NAG has been used to plan investigative questions in a detective mystery scenario by generating plausible scenarios based on evidence. It''s quite impressive to see NAG finger the killer!

Cheers,

Timkin

I had a look at the Itchy and Scratchy NAG site, but it seems not to be working
Also what obvious problems do PS have?
I know that if you remove one part you are likely to crash the entire system and also that you are unable to commit to 2 different possibilities in the ''action'' bit.
Anything else that i''ve obviously missed?

I don''t know what a production system is but I have been thinking about an advance semantic netowrk design that could store any sentence as relationships and I have come up with one.

Basically, each link can have links coming ot of it describing the link. Two links for example may be linked together with an "and" link.

I don''t know what a production system is but I have been thinking about an advance semantic netowrk design that could store any sentence as relationships and I have come up with one.

Basically, each link can have links coming ot of it describing the link. Two links for example may be linked together with an "and" link.

Puzzler - the problem with that type of sematnic network is ambiguity
would it ever be able to differentiate
''they are killing apples''
maybe the apples are a type called killing apples, or someone is killing some apples. What makes it even harder is that as is, humans are unable to differentiate, therefore a computer wont be able to either.

If you''re looking into storing sentences, then you should take a look at the natural language processing side of things, with ideas such as conceptual graphs and scripts. Semantic networks are also well covered in this field in a bit more depth than you have gone into so far. But the only real foolproof answer to get around ambiguity is to replace ''natural'' language with a more formal language that cannot be misinterpreted.

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quote: Original post by Theyarv
Also what obvious problems do PS have?

Efficiency is the main problem. The more rules you put into the system, the harder it is to get anything useful out of it. Also, the commonly implemented conflict resolution strategies tend to deal with the most recent, highest priority rules. This can keep the system from processing older, less apparently important information that may indeed turn out to be useful.

Of course, this is not to say that PSs cannot be made to ''do good work''! Take SOAR for example... not too shabby if I may say so!

Cheers,

Timkin