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Re: Meaning of URIRefs

From: Sandro Hawke <sandro@w3.org>
Date: Fri, 25 Oct 2002 15:11:49 -0400
Message-Id: <200210251911.g9PJBnq25431@wadimousa.hawke.org>
To: pat hayes <phayes@ai.uwf.edu>
cc: www-rdf-interest@w3.org


> >The way around these problems is to split definitional content and
> >general content into different documents.
> 
> The trouble with this kind of reply is that it requires all web users 
> to obey unspoken and hard-to-define rules of good behavior.  Note 
> that you, Sandro, were at pains to explain in your earlier message 
> that 'definitional' didn't have any sharp meaning. A very good point; 
> but then it is hardly reasonable to immediately require that all web 
> users segregate their content into documents according to whether or 
> not they satisfy this meaningless distinction.
>
> BUt more seriously, we can SAY things like this all we want, but 
> people will not in fact do it. Are you going to try to tell, say, 
> Nokia, that they must segregate all their RDF content into different 
> documents according to whether or not they are considered 
> 'definitional'? They would (correctly) laugh at you.

(There's some lag in this message chain, so perhaps I've already
addressed this to your satisfaction.  But I'll err on the verbose
side.)

I can suggest to Nokia that if they segregate their data carefully,
they will be facilitating use and reuse of the data.  It's not unlike
HTML web sites, where there is ongoing tension between
lazy/short-sited design and good design, where good design has all
sort of benefits which may not be immediately obvious.

The segregation into definitional and non-definitional triples is
certainly an art, but perhaps it's not as black as it seems.  DAML
users don't seem to have much trouble distinguishing between ontologies
and instance data.  I haven't seen a lot of URIRefs pointing into
instance data from other instance data, and I'm not sure what exactly
people intend when they do that.  

Does someone have some real uses cases where this segregation does NOT
seem like good information architecture?  Note that in many cases it's
completely arbitrary in authoring RDF whether, when you say
   
     rdf:about="&foo;bar"

the &foo; entity is the document's own URI.  (If it is, it's the same
as rdf:ID, give or take a hash mark.)  People often do it because
they're not sure what else the foo might point to.  If they make this
segregation, it would become clear.  &foo; is the definitional
document.  Make it empty if you really have nothing definitional to
say, but you can probably come up with something useful.

   -- sandro
Received on Friday, 25 October 2002 15:12:29 GMT

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