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Re: Ill-typed vs. inconsistent?

From: Eric Prud'hommeaux <eric@w3.org>
Date: Mon, 12 Nov 2012 10:41:17 -0500
To: Sandro Hawke <sandro@w3.org>
Cc: Pat Hayes <phayes@ihmc.us>, Richard Cyganiak <richard@cyganiak.de>, RDF Working Group WG <public-rdf-wg@w3.org>
Message-ID: <20121112154115.GA2137@w3.org>
* Sandro Hawke <sandro@w3.org> [2012-11-12 10:20-0500]
> On 11/12/2012 02:58 AM, Pat Hayes wrote:
> >On Nov 8, 2012, at 1:13 PM, Richard Cyganiak wrote:
> >
> >>What's the relevance of the distinction between “graphs containing ill-typed literals” and “inconsistent graphs” in the Semantics?
> >The relevance is that it is quite possible to say sensible (and therefore consistent) things about ill-typed literals, such as that they are ill-typed.
> >
> >>The text stresses that the presence of an ill-typed literals does not constitute an inconsistency.
> >>
> >>But why does the distinction matter?
> >I am not sure what you mean by "the distinction" here. Why would you expect that an ill-typed literal would produce an inconsistency? Why would the presence of an ill-typed literal make a triple false?
> >
> >>Is there any reason anybody needs to know about this distinction who isn't interested in the arcana of the model theory?
> >I'm not sure what you consider to be "arcana". Someone who cannot follow the model theory probably shouldn't be using RDF.
> 
> Pat, I think a lot of people should be using RDF who are not
> interested in the model theory.  It's a bit like people buys nails
> at the hardware store without knowing all the materials
> characteristics of the metal used.  (Whether they *can* understand
> the materials science is irrelevant, of course.)
>
>      -- Sandro

The problem burgeoning popularity of RDF is all these damned dilettantes.
Clearly we need to raise the bar a bit.

> >> From the perspective of someone who authors RDF data, or works with RDF data, they both seem like belonging to the same class of problem, and I'm a bit at a loss as to how to explain the difference.
> >To me they seem quite obviously different, so apparently I am not following your intuition here. FWIW, one should *not* think of inconsistency as a kind of error condition. (Maybe the semantics text should spend a little time explaining this point.)
> >
> >>(I know how both terms are defined and what conditions exactly cause them; the question is about why the spec insists that ill-typed literals do not cause a graph to be inconsistent.)
> >My question, in reply, would be to ask why anyone would think it would.
> >
> >Pat
> >
> >>Best,
> >>Richard
> >>
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> >
> >
> >
> >
> >
> >
> >
> 
> 

-- 
-ericP
Received on Monday, 12 November 2012 15:46:11 GMT

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