Re: comments on http://www.w3.org/TR/2006/NOTE-swbp-n-aryRelations-20060412/

C. M. Sperberg-McQueen wrote:
> 
snip
> 1) I was surprised that the document appears nowhere to address what
> seems to me to be one of the pre-eminent issues with the use of
> Pattern 1: it involves ontological commitments that may be
> uncongenial.
> 
> It may well be the considered opinion of the WG that the engineering
> arguments in favor of reifying relations as Pattern 1 does must
> outweigh the philosophical arguments that might be brought to bear
> against attributing existence to, or making individuals out of,
> events, actions, or anything else one might typically describe with an
> n-ary relation.  But if so, that fact is worth recording.
> 
> Since bad philosophy so frequently makes for bad engineering, I'm not
> sure whether the engineering convenience does outweigh the
> philosophical objections Quine or others might feel to treating
> diagnoses, or even purchases, as individuals.
> 
A minor comment:

This is a good point, and probably deserves some discussion.  However, I 
don't think the boundaries between the engineering arguments and the 
philosophical ones are all that clear cut.   I think the key point you 
make is "it involves ontological commitments that may be uncongenial". 
If I'm interpreting this correctly, you're not saying these commitments 
are necessarily *wrong*, just "may be uncongenial".  And this is true. 
The limitation to binary relations may force me to adapt the model of 
the situation I have in my head to the closest thing I can write in the 
notation (RDF in this case) I have at my disposal.

I've commented on at least one other occasion that this note would be 
more complete (and possibly helpful) if it were accompanied, possibly in 
a separate note, by some discussion of the relationship between this 
issue and how things are modeled in relational databases.  I bring this 
up here because modeling things in relational databases (which is, after 
all, pretty common) raises the exact opposite problem to the one you 
mention:  since the only thing allowed in a relational database is an 
n-ary relation, people are forced to model what they might typically 
describe with an individual as a tuple in an n-ary relation instead. 
Whether it ought to or not, this mostly doesn't seem to bother anyone. 
Having to break up n-aries into binaries bothers people, and that's 
mostly because it's more work both to create the binaries, and to 
aggregate the information about a single individual back when you need 
it.  People complain about highly-normalized relations in relational 
databases (which are often good "engineering") for similar reasons.

Regarding the "bad philosophy", how bad is it?  I can understand qualms 
about some things, but what are the philosophical objections to treating 
purchases as individuals?   It certainly seems more natural to treat 
that piece of paper I take home from the store as a record of 
information about an individual "something" than as a record of an 
instance of an n-ary relation.  (I don't intend this as any kind of 
sneer at philosophy;  this is a serious question).

--Frank

Received on Saturday, 22 April 2006 16:16:35 UTC