innovation in metadata design, implementation & best practices

Title: DC property domains and ranges
Main agenda:
Modified: 2005-09-04 16:10, Sunday

In the context of a recently constituted DC RDF Task Force
[2], Andy has posted a draft tentatively assigning domains
and ranges to DC properties [1]. The document also provides
a tentative listing of classes that would be needed (or
desirable) in order to do this right.

This exercises raises the question of what "defines" a DCMI
metadata term and, more specifically, the relative status of
Web documents as opposed to the RDF schemas as "definitive"
and "authoritative" representations of DCMI terms.  

Currently, the Web page at
asserts itself to be "an up-to-date, authoritative
specification of all metadata terms maintained by DCMI".  

DCMI currently makes no such claims for the RDF schema
representation of its terms. Indeed, the only policy statement
on the subject, at, says that
"users of RDF guidelines and schemas posted on the DCMI Web
site need to be aware that these resources may be subject
to change based on the results of further discussions within
DCMI and W3C" -- a situation that can hopefully be remedied
by the work of the DC RDF Task force.

If in addition to the "natural-language" definitions
currently provided in the Web documents, DCMI were also
to provide "definitive" RDF schemas, then DCMI would be
saying, in effect, that its terms are defined not just by
natural-language definitions, but also by the sum of formal
assertions and relations, within which the terms are embedded,
as expressed in the RDF schema.

We would need to consider whether it would be realistic for
DCMI to claim that both the Web document and the RDF schema are
"authoritative" -- raising the bar for keeping the documents
not only in synch, but for expressing formal assertions
adequately in the Web documents -- or whether one should be
definitive while the other is considered to be derived.

The finalization of authoritative assertions along the lines
of [1] has implications for DCMI process, as they would
presumably be subject to review and maintenance by the Usage
Board (or a functional equivalent).

In Madrid, Andy will present this work for discussion, though the 
work is still at too preliminary a stage for action by the Usage Board.

[1] DC property domains and ranges - draft

[2] DC RDF Task force
[3] Guidelines for encoding DC metadata using the RDF model
[4] Clarification of the recommendations for encoding 'value strings'
     in DC RDF/XML