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Re: Red herring Re: naive question: why prefer absolute URIs to # URIs for linked data?

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Date: Fri, 2 Sep 2011 15:11:14 -0400
Message-ID: <CAFKQJ8=q7ou8GyuT-xjMjkVVF7ohrOpS8HtJcNzLM1f4hdoB_Q@mail.gmail.com>
To: Tim Berners-Lee <timbl@w3.org>
Cc: Ian Davis <me@iandavis.com>, Jonathan Rees <jar@creativecommons.org>, Harry Halpin <hhalpin@ibiblio.org>, Manu Sporny <msporny@digitalbazaar.com>, www-tag@w3.org
On Fri, Sep 2, 2011 at 2:50 PM, Tim Berners-Lee <timbl@w3.org> wrote:

>
> On 2011-08 -31, at 17:39, Alan Ruttenberg wrote:
>
> > Spot on. Couldn't agree more.
> > -Alan
> >
> > On Wed, Aug 31, 2011 at 4:52 PM, Ian Davis <me@iandavis.com> wrote:
> >> I think there are a number of contributing factors:
> >>
> >> 1) architecturally the meaning of the fragment is determined by the
> media
> >> type of the representation. Thus meaning of a hash URI depends on how
> you
> >> access it.
>
> Let me first declare this a red herring.   It is convenient to
> be able to server a file up say in RDF/XML and N3 and content negotiate,
> but a condition of doing this is that the meaning is NOT changed between
> the two.
> Any more than if you served a document saying
> "It is sunny" in text/html and one saying "it is rainy" in
> application/xhtml+xml.
> Typically with for example rdf/xml and turtle, the same RDF graph is
> sent.
>

You are correct. I should have read his words more carefully. I believe,
however, that he meant not that "the meaning depends on how you access it"
but rather "the protocol for determining what a fragment refers is
determined by the media type". In other words, that we are not free to give
an (authoritative) interpretation of the meaning of a fragment in every
case. Doing so, for a media type that gives a conflicting interpretation for
a fragment identifier,  would be something like defining the meaning of URIs
in domains of which you are not owner.

-Alan

>
> We could quibble around the edges of this, but basically
> it i not a valuable way to spend time.
>
> And the meaning any document  you get back even if you *don't* use a
> hashURI depends
> on the media type in exactly the same way. So the meaning
> of the original URI referred to in that document similarly would depend on
> the media
> type to the same extent.
>
> Now to the more interesting questions in another message.
>
> Tim
>
>
Received on Friday, 2 September 2011 19:12:12 GMT

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