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RE: Issue rdfms-assertion

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Sun, 18 Nov 2001 12:30:02 +0000
Message-Id: <>
To: Dan Brickley <danbri@w3.org>, <w3c-rdfcore-wg@w3.org>
At 11:51 16/11/2001 -0500, Dan Brickley wrote:


>Yes, though we need to go a little further than we have to date in
>claiming that RDF content is meaningful. We then need W3C et al to provide
>document formatting and protocol contexts (XHTML, SVG, mime, HTTP,
>SOAP...) within which this meaningful content can be exposed.
>RDF data *isn't* an arbitrary graph structure, and DanC is write to say
>that we need the RDF spec to be clear on this. We claim that RDF data can
>be _about_ things in the world. The Model Theory alone doesn't give us
>that. RDF uses the URI specification as its primary means of anchoring 
>graphs to the physical and social world. The meaning of a piece of RDF
>isn't fixed by the MT alone, but by the meanings that the URI spec
>plus deployed Web practice gives to URI name strings. The meaning of RDF
>content is furthermore fixed by the prose and rules associated with the
>schemas/ontologies it draws upon. Where  those definitions are murky, the
>meaning of RDF instance data is murky.
>This is fine. We should say things to the effect that...:
>  (i) RDF content has, on a good day, propositional content; it corresponds
>      to statements or propositions about entities in the real 
> social/legal world
>(ii) the Model Theory assumes such a correspondence, but does not itself
>      specify one.
>(iii) the correspondence between RDF content and propositions about the
>      world is fixed in part by facts about individual URI names (ie. what
>      they denote); in part by facts about the URI specification (rules
>      about how URI names can denote, (sometimes) fail to denote, etc.);
>      in part by the machine-readable rules associated with classes,
>      properties, and indivduals mentioned in the RDF content (or
>      indirectly through the schemas/ontologies used); and in part by
>      the natural language definitions specified in these schemas.
>(iv) the formal components of RDF (MT etc.) do not guarantee that any
>      piece of RDF instance data is meaningful, or that it corresponds to
>      propositional content.  It may use incoherently
>      designed or inadequately defined classes and properties; or it may
>      use URI names whose referents are for some reason unclear or 
> indeterminate.
>(v)  While the RDF design explicitly notes that RDF is intended to have
>propositional content, despite these various obstacles, the core RDF specs
>are agnostic regarding the various options for deploying this content in
>the Web. In particular, RDF core does not enumerate the XML vocabularies
>within which it may be embedded and retain its propositional nature
>nor define mechanisms that distinguish the roles played by the XML
>elements that may contain it in wellformed XML  markup. RDF Core does not
>claim that all XML document and data formats can be interpreted as having
>propositional content, but notes for eg. that SVG's 'metadata' element and
>(X)HTML's 'head' element are commonly understood in
>this way. Similarly, the Core specs don't address protocols (HTTP) or
>container formats (MIME), nor attempt to associate the propositional
>content of RDF data with any particular real world entities such as
>webmasters, document authors, editors, service providers.

Definitely.  Can we take this as a starting point?

Received on Sunday, 18 November 2001 08:29:55 UTC

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