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Re: lcsh.info RDFa SKOS and content negotiation - use of RDF-style # IDs in RDFa?

From: Dan Brickley <danbri@danbri.org>
Date: Mon, 06 Oct 2008 13:53:37 +0200
Message-ID: <48E9FC41.3030703@danbri.org>
To: Steven Pemberton <steven.pemberton@cwi.nl>
Cc: "Williams, Stuart (HP Labs, Bristol)" <skw@hp.com>, Pat Hayes <phayes@ihmc.us>, RDFa <public-rdf-in-xhtml-tf@w3.org>, "www-tag@w3.org WG" <www-tag@w3.org>, Ed Summers <ehs@pobox.com>

Steven Pemberton wrote:
> On Fri, 03 Oct 2008 17:12:55 +0200, Williams, Stuart (HP Labs, Bristol) 
> <skw@hp.com> wrote:
>>> I like Larry's scheme as well, but the time bit is either too little or
>>> too much, because once you start allowing for the primary topic of a
>>> resource changing over time, well, then why not foaf:name of a 
>>> person, or w3c:isEditorOf a spec, or any property really.
>> Well... because they do change (and raw RDF lacks a temporal 
>> dimension). Good governance can seek to restrict the ravages of 
>> time... but time will outlive us all and all our institutions...
> I'm not sure if you're teasing me or not. What I meant was, I am unsure 
> of the value of being able to say that a primary topic has a temporal 
> dimension, if you can't say that about anything else in RDF.

There's a trick here. Choose your properties with care.

The foaf:mbox property, for example, has built in temporal constraints.

personal mailbox - A personal mailbox, ie. an Internet mailbox 
associated with exactly one owner, the first owner of this mailbox. This 
is a 'static inverse functional property', in that there is (across time 
and change) at most one individual that ever has any particular value 
for foaf:mbox.

Even though we can't decorate RDF instance data with triple-by-triple 
temporal annotations (and would we really want to?), there are things we 
can say at the schema level. I'm curious for Pat's perspective on 
whether any such notion of a 'static inverse functional property' could 
be formalised cleanly, or whether the concept crumbles under inspection...



Received on Monday, 6 October 2008 11:55:55 UTC

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