- From: Barry Norton <barry.norton@ontotext.com>
- Date: Mon, 03 Jun 2013 21:58:20 +0100
- To: public-lod@w3.org
On 03/06/13 16:52, Phillip Lord wrote:
>
> Value unknown is easy. Just don't say anything.
>
> Value not applicable and doesn't exist, given your examples, seem the
> same to me.
I don't agree. Under the Open World assumption anything that can later
be learned should not affect consistency. A positive null ("there is no
such") should lead to a contradiction is someone later asserts such a
value/relationship (which doesn't happen with a simple unpopulated
relationship from the subject).
In RDF (which has been my answer before - feel free to contradict me,
I'm not an authority, it's just that I've made the proposal before) this
seems possible only with Collections. What I mean by this is that with a
list-ranged relationship I can specify a value of 'there is no such'
(rdf:nil) and someone trying to populate the list later would have to
revert that fact to provide such a value. Without a list expected, this
does not seem possible (again, to me).
Barry
Received on Monday, 3 June 2013 20:58:49 UTC