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Re: Media types and assertions

From: Mark Baker <distobj@acm.org>
Date: Fri, 12 Mar 2004 15:21:24 -0500
To: Pat Hayes <phayes@ihmc.us>
Cc: www-rdf-comments@w3.org
Message-ID: <20040312152123.B32552@www.markbaker.ca>

On Fri, Mar 12, 2004 at 01:27:09PM -0600, Pat Hayes wrote:
> >On Fri, Mar 12, 2004 at 09:42:50AM -0600, Pat Hayes wrote:
> >>  >So in those terms, I claim that whether or not an RDF document is
> >>  >asserted is something the publisher of that document needs to make
> >>  >clear via the messages they send.
> >>
> >>  But why do you claim this?
> >
> >Because it's part of the meaning to be communicated.
> >
> >I think we need to agree on that, or else we're just going to be
> >spinning our wheels here.
> 
> Maybe. I don't agree on that. That is, at least, there is a clear 
> sense of 'meaning' in which its not part of the meaning being 
> communicated. And I don't think that ANY web protocols have ever 
> attempted to deal with communication of any sense of 'meaning' which 
> does encompass intent. What's the media type for making a promise in 
> HTML? Or for being sarcastic?

Yes, certainly, that's not something that media types or HTML need to
worry about because some semantics are hidden from automata by virtue of
HTML being a human-targetted format.

But if we developed a "promise" ontology so that we could communicate
promises between automata using RDF, I think we'd also need to be able
to know when the promise is intended, versus just a description of a
promise and not intended, because the bits sent are identical, yet the
semantics are quite different.

> >customers are seismographic network operators, and the last thing they
> >want is to have their simulated earthquake data be interpreted as real
> >earthquakes by the rest of the network. 8-O
> 
> Well, OK, then I agree in cases like this its important to 
> distinguish real data from fake or sample data. Moral: find a way to 
> reliably distinguish them, and agree on it.

I don't want my customers to have to establish pair-wise agreements
to deal with this, nor do I want to try to gather the seismic industry
together to do so.  I would like to use existing widely deployed
mechanisms on the Web for signally this sort of agreement, and media
types currently fit the bill, IMO.

> That's not the same as 
> the asserted/nonasserted distinction. I can make asssertions about 
> fake data just as easily as about real data. I might, for example, 
> want to positively assert that it is not real data.

Ok, but I want to do that self-descriptively.  I don't want a customer
to grab some data from one URI, but miss the data from some other URI
which asserts that the other data is unasserted.  I want that indicated
in the message returned from the first URI.  Do you know any other way
I can do this that's currently well deployed?

> BTW, publishing fake data is always a risky business on an open 
> network. I'd advise your clients to just not do it at all, or to use 
> a distinctive data format to do it in, so as to remove the very 
> possibility of confusing fake with real data.

Agreed, measures should also be taken to ensure that test data doesn't
escape.  But I don't want to have to depend upon that since data has a
way of escaping.  So as a measure of last resort, I want the
representation itself (document + media type) to declare that it's test
data.

Mark.
-- 
Mark Baker.   Ottawa, Ontario, CANADA.        http://www.markbaker.ca
Received on Friday, 12 March 2004 15:19:26 UTC

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