- From: Dan Brickley <danbri@danbri.org>
- Date: Mon, 06 Oct 2008 13:53:37 +0200
- 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. http://xmlns.com/foaf/spec/#term_mbox [ 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... cheers, Dan -- http://danbri.org/
Received on Monday, 6 October 2008 11:55:55 UTC