- From: Dan Brickley <danbri@danbri.org>
- Date: Wed, 19 Nov 2008 14:09:12 +0100
- To: Pierre-Antoine Champin <swlists-040405@champin.net>
- Cc: Paul Gearon <gearon@ieee.org>, Semantic Web <semantic-web@w3.org>
Pierre-Antoine Champin wrote: > Paul Gearon a écrit : >> While I'm here, I also noticed Tim Finin referring to "domain and range >> constraints". Personally, I don't see the word "constraint" as an >> appropriate description, since rdfs:domain and rdfs:range are not >> constraining in any way. > > They are constraining the set of interpretations that are models of your > knowledge base. Namely, you constrain Fido to be a person... > > But I grant you this is not exactly what most people expect from the > term "constraint"... I also had to do the kind of explainations you > describe... Yes, exactly. In earlier (1998ish) versions of RDFS we called them 'constraint resources' (with the anticipation of using that concept to flag up new constructs from anticipated developments like DAML+OIL and OWL). This didn't really work, because anything that had a solid meaning was a constraint in this sense, so we removed that wording. This is a very interesting discussion, wish I had time this week to jump in further. I do recommend against using RDFS/OWL to express application/dataset constraints, while recognising that there's a real need for recording them in machine-friendly form. In the Dublin Core world, this topic is often discussed in terms of "application profiles", meaning that we want to say things about likely and expected data patterns, rather than doing what RDFS/OWL does and merely offering machine dictionary definitions of terms. cheers, Dan -- http://danbri.org/
Received on Wednesday, 19 November 2008 13:09:55 UTC