RE: [OEP] Draft of a note on n-ary relations

Hello Natasha

> > "John buys a "Lenny the Lion" book from Mary for $15 as a birthday
> > gift."
> >
> > Should read certainly
> >
> > "John buys a "Lenny the Lion" book for $15 *for* Mary as a birthday
> > gift."
>
> Actually, it's me not using the right words again (see a pattern here?
> :) a different kind of one, I suppose).
>
> What we actually had in mind was indeed that John buy the book *from*
> Mary for a birthday gift for someone. So Mary was the recipient of the
> $15.

Wow! This is another story that the one I caught, indeed :(

> So, by trying to use the generic roles of "recipient" and "agent,"
> we've obscured the issue. I guess it would be better to use simply
> "buyer" and "seller".

Or replace "Mary" by "Amazon", and ask them to sponsor the document :))

> We can still omit the amount not to get into that
> discussion or just mention it and cross-reference the forthcoming
> pattern on quantities.

Right

> I would still go with the purchase example as its slightly more
> straightforward than the gift one (on the gift side, one might wonder
> for example if Mary and Mary's birthday should somehow be connected,
> etc.)

Yes, and other noisy semantics like what is the kind of relationship between John and
Mary.
Sticking to the business relationship is safer ...

> > Mary should not know anything about the former, and certainly not the
> > amount - that would
> > be considered as rude from John, at least in France, maybe not in
> > America, where $ is the
> > measure of everything :))
>
> no, don't worry, even in America you don't usually flaunt the price of
> your gift :)

Happy to see America is not that far from civilization after all :))

> > Another picky remark : the identification of the gift object is
> > somehow fuzzy here.
> > Is it an individual copy, or the generic publication defined e.g. by
> > its ISBN number as
> > discussed before?
> > Accurately, it's a random instance of the publication, before the
> > purchase, and it becomes
> > a singular, identified one as soon as it is signed up by John ("To
> > Mary, for her 7th
> > birthday - John") and offered.
> > Should the example capture that, or sweep the difficulty under the
> > carpet ?
>
> I'd say sweep -- the difference in representing a physical copy of the
> book and a generic publication is certainly out of scope here.

Agreed. Just put that remark to point out that any apparently simple situation can be made
arbitrarily complex (and arbitrarily confusing for the user) depending on how carefully
you look at it. This is a general issue we should maybe address at some point.
Reminds me of a famous quote by a French humorist of the 70's:
"A technocrat is that kind of guy, when he answers you, you don't understand your question
any more."

Cheers

Bernard

Bernard Vatant
Senior Consultant
Knowledge Engineering
Mondeca - www.mondeca.com
bernard.vatant@mondeca.com

Received on Tuesday, 11 May 2004 03:45:05 UTC