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I have to go shopping in Cardiff. I need to get the following:
- The latest Soundgarden CD.
- A birthday present for a friend.
- This month's Sound on Sound magazine.
- A bottle of wine for tonight's dinner.
What present do I get my friend?
I know he likes modern Jazz. I know Herbie Hancock has new CD out. I decide to
get that for him.
What wine do I get?
I am cooking beef with black bean source tonight so a good red wine would be in
order. A French Burgundy would be nice.
What reasoning has gone on so far?
Quite a lot
- I know my friend likes Jazz.
- Recently from the Internet Newsgroups I have -
updated my knowledge - that the Herb has a new CD out.
- The fact that it is new means that there is a good chance he does not
have it already.
- (Also I do not have it so I can
tape it).
- I know what meal I intend to cook.
- Red wine goes well with red meat and I know that Burgundy is nice
wine.
Where to buy?
There are many possibilities:
- I know Spillers records are generally the cheapest store with a
decent stock.
- But I also know they do not have a large stock of Jazz CDs.
- I therefore decide to try Spillers first for both CDs.
- The Virgin Megastore has the largest selection of Jazz CDs so I'll go
there if not successful.
- Since I am going to the bottom area of Cardiff I decide to try
Oddbins for the Wine
What reasoning has gone on now?
- We have know decided which stores to visit and our basic route.
- This is a planning problem. This is basically a search problem:
- there are a variety of possible shops
- I choose them to allow effective shopping.
- A lot of knowledge has been used (e.g):
- The locations of the shops.
- What they stock (and general prices).
- We have used this knowledge to help us select our shops:
- Generally,unconstrained search is hard -- A hallmark of
intelligence is the use of knowledge to make search problems more tractable.
How could a computer achieve this?
NOTE: This would be a very difficult task.
- Capture knowledge -- Encode knowledge in a ``language''. At least
two forms of knowledge.
- Certain -- My friend likes Jazz, Street plan of Cardiff.
- Probable -- I can find a suitable CD in Cardiff.
Knowledge encoding is a difficult task. We will see this later in the course.
- Search knowledge for solution. Could do this by:
- Enumerating every combination of CD shop, Wine Merchant, Newsagent
OR
- Use information about shop locations etc. to constrain or search. OUR
CHOSEN METHOD.
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Up: Artificial Intelligence II -
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dave@cs.cf.ac.uk