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C00002 00002			Exercises for Lecture 6 ... CS266 Winter 75.... Jan 23
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		Exercises for Lecture 6 ... CS266 Winter 75.... Jan 23


1.)   Draw an associative net in which the following facts are incoded
by links which include token and type nodes:

Dogs, cats, mice, and rabbits are animals.
All living creatures eat some sort of food.
Dogs are generally bigger than cats.
Fido is a dog.
Hyper is a cat and eats mice.
Dogs chase cats and rabbits.
Cats chase mice.
Hyper is the same size as a rabbit.
Fido is a big dog.

Describe the set of links and nodes that were needed for this
representation of the information.  Be especially explicit concerning
how your network distinguishes between general concepts and specific
instances of a concept. 

Restate the information that is directly recoverable from your net in
the sort of English that a fairly simple program could produce by
following the links (I'll call this form "Tarzan" English). 

For each of the following questions, show the "Tarzan" form to which
the hypothetical English processor would convert it in order for the
net searcher to handle it.  Show the paths followed and describe the
general algorithm used to find each answer.  (Warning .. the answer
may be "I don't know" or may require adding extra information to the
net somewhere.  If you must add information, tell what you added and
why.) For questions where simple following of the net doesn't yield
a clear answer, postulate an inference scheme that produces a more
human-like answer.

Are dogs animals?
How big is a dog?
Is Hyper a dog?
What do you know about cats?
What do cats eat?
What animals are smaller than Fido?
Does Fido eat cats?


2.)  Assume that the associative net shown here from Lindsay and Norman's
"Human Information Processing" represents a subset of the facts known
by some person. List in "Tarzan" English the facts that are directly
recoverable from the net. What sorts of information are left out
of the simple case grammar used for the circled relations?