W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > July 2001

Re: A use case for anon nodes - action from telecon

From: pat hayes <phayes@ai.uwf.edu>
Date: Thu, 26 Jul 2001 16:47:13 -0700
Message-Id: <v04210122b7865a7d9094@[]>
To: Brian McBride <bwm@hplb.hpl.hp.com>
Cc: w3c-rdfcore-wg@w3.org
>pat hayes wrote:
> > No, of course not. But the original example seemed to involve some
> > kind of transaction or handshaking (?) going on between the buyer and
> > the seller, mediated by some kind of relationship between the RDF
> > smears (good word!) they have published, ie this RDF-publishing is
> > supposed to be in some commercial context of actual activities.
>It seems as though the context has some significance in how we
>view this scenario.  The participants have intent to establish
>commercial transactions.  Lets try a thought experiment, change
>the scenario and see how that affects how we look on it.
>Two folks, Anna and Bertie have home pages on the web.  For no
>other reason than its the done thing to do to be hip, they
>include in their home pages RDF statements about where they live
>and where they work e.g.
>  <Anna>      <livesAt> _:AnnasHome .
>  _:AnnasHome <zipcode> "12345" .
>  <Anna>      <worksAt> _:AnnasWork .
>  _:AnnasWork <zipcode> "54321" .
>  <Bertie>      <livesAt> _:BertiesHome .
>  _:BeritesHome <zipcode> "12345" .
>  <Bertie>      <worksAt> _:BertiesWork .
>  _:BertiesWork <zipcode> "54321" .
>Pure assertions, yes?  No query, yes?  No intent to create
>a relationship, yes?

True, all true.

>Friends of the Planet have noticed this hip behaviour and they
>have a web crawler that sucks up this information and looks
>for folks with close home and work zip codes and sends them
>email suggesting they might like to car share.
>Seems to me that the processing that goes in this scenario and
>the original are effectively the same.  The point is, that the
>query, if there is one, is a feature of a third party, not of
>the publishers of the RDF.

Ah. OK, as long as we are clear about that, then I agree. I was under 
the impression (and I can no longer remember where this came from, or 
if I just imagined it) that the buyer/seller scenario was supposed to 
be a case where the seller said something existed (to do with 
flowers) and the buyer said he *wished* that something existed, or 
maybe that he was *asking* if something existed, and that was the 
basis on which the match-making worked. If they are both just telling 
the world something, then *everyone* is making assertions.

(I would just mention , though, that FotP are going to be using 
internal inferencing that goes beyond anything that Anna and Bertie 
have said. Which is fine, of course; just thought I'd mention it.)

>BTW, Anna has two homes, both with the same zipcode.

Sure, no sweat. She's only mentioned one of them, but that doesnt 
stop her having more. (Who is this 'Berites' guy, though?)

> > Once
> > we talk about things that are done with, or as a result of,
> > publishing some RDF, we need to be clearer about what relationships
> > are being assumed between the RDF that is being published. There is a
> > real difference between asserting an existential (saying something
> > exists) and holding up an existential as a challenge for someone else
> > to prove (eg saying I need someone to sell me some roses, and
> > expecting this to somehow extract all the RDF that talks about
> > selling roses.) (Eg skolemisation is OK in the former case, not the
> > latter; variables can get bound at inference-time in the latter case,
> > not the former.) If both the buyers and the sellers are just making
> > assertions, then they can both draw all sorts of conclusions, but
> > nobody is going to discover anything about themselves that they didnt
> > already know, so no roses are going to actually get sold.
>I don't dispute that different processing may be required in
>different circumstances.  But those circumstances may not depend
>on the intentions of the publishers of the RDF.
>Does this shed any light on where I'm going wrong?

Yes, thanks.

>My brain is beginning to hurt.

Eat your spinach and you will be fine.


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Received on Thursday, 26 July 2001 19:47:03 UTC

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