- From: Thomas Baker <thomas.baker@bi.fhg.de>
- Date: Fri, 25 Feb 2005 16:23:21 +0100
- To: Benjamin Nowack <bnowack@appmosphere.com>
- Cc: "Miles, AJ (Alistair)" <A.J.Miles@rl.ac.uk>, public-esw-thes@w3.org
Benjamin, On Fri, Feb 25, 2005 at 03:36:30PM +0100, Benjamin Nowack wrote: > Just some food for thought: > > I know that it's perfectly legal in non-DL RDFS space to > have hybrid properties, but given that e.g. dc:creator > has already caused a lot of confusion and needs rules > or application-specific extensions to be processed > without problems, wouldn't it make sense to separate > datatype props from object props or to limit certain > documentation props to literals? By "hybrid properties", do you mean properties that can be associated either with literal values or with resources in themselves? If so, it is true that this basic tension has been the cause of much confusion, particularly but not exclusively with regard to dc:creator. If so, I can report that in the DCMI context, this problem has been resolved with the formulation of a DCMI Abstract Model [1]. The model, which is essentially RDF-compatible but couched in legacy DCMI terminology, is intended for use as a point of reference for comparing the expressivity of different encodings of Dublin Core, such as XHTML, XML and RDF/XML. The Abstract Model says that the value of a DCMI metadata term is by definition a resource, even if the representation of that resource is in some encodings limited to a string value. The Abstract Model work was itself a response to confusion in the implementor communities -- confusion that was determined in large part by the possibilities of different implementation scenarios. In the course of untangling these issues, we have ended up in the DCMI Usage Board with a bias against building implementation-related restrictions into the very definitions of the vocabulary. Limiting values to literals, for example, can perhaps more appropriately be done in some sort of application-profile construct rather than "once and for all" in the canonical representation of the vocabulary. Tom [1] http://dublincore.org/documents/abstract-model/ -- Dr. Thomas Baker Thomas.Baker@izb.fraunhofer.de Institutszentrum Schloss Birlinghoven mobile +49-160-9664-2129 Fraunhofer-Gesellschaft work +49-30-8109-9027 53754 Sankt Augustin, Germany fax +49-2241-144-2352 Personal email: thbaker79@alumni.amherst.edu
Received on Friday, 25 February 2005 15:20:38 UTC