I agree this is interesting. I guess this is quite likely to become the norm (if it isn't already).

On that basis, I suppose one could argue that a success criteria for DCMI will lie in the use of our ontology as a kind of secondary 'equivalence' or 'switching' layer between other ontologies, rather than (or as well as) in its direct use in instance metadata ?

Andy

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Andy Powell
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-----Original Message-----
From: DCMI Architecture Forum [mailto:[log in to unmask]] On Behalf Of Thomas Baker
Sent: 14 August 2010 16:32
To: [log in to unmask]
Subject: Dublin Core in W3C Ontology for Media Resource

I note with interest, in "Ontology for Media Resource 1.0,
W3C Working Draft 08 June 2010" [1] that, while strongly anchored
in the Dublin Core vocabulary, the specification defines its
own properties with "mappings" to DCMI metadata terms, with the 
following rationale:

    The ontology defines mappings between a set of vocabularies
    and a set of core properties in our own namespace, which is
    identified with the "ma" prefix in this document. Although
    some of these properties can appear to be redundant with
    the Dublin Core set of properties, the set of properties
    that make up our ontology are defined in a new namespace
    that is separate from the Dublin Core for several reasons,
    including:

    * Dublin Core is only one of the vocabularies that mappings 
      are defined for.

    * The Dublin Core set vocabulary does not cover all of our
      needs; hence, we would still have to create new properties
      in our own namespace.

    * More importantly, the Dublin Core properties have
      been created with a set of restrictions. While these
      restrictions are in general somewhat loose, we may want
      to apply other restrictions to our properties. Therefore,
      we have to define our own set of properties that we can
      control (e.g., by constraining their allowed values);
      hence, these properties cannot be dependent on any one
      (or even several) external source(s) of authority for
      the definition of our core mapping.

   For a practical use of the media ontology in an API,
   we define type restrictions for our properties that go
   beyond the generic Dublin Core specification.

Some relevant mappings can be found in 4.2.2.3 (EBUCore),
4.2.2.8 (MediaRDF), and 4.2.2.16 (XMP) [2,3,4].

As Felix Sasaki explains in [5], the mappings in [1] are
designed for converting between fixed formats (EBUCore,
MediaRDF, XMP, etc) using API methods defined in [6],
but an RDF-based ontology (possibly with formally defined
mappings?) is on the way.

Tom

[1] http://www.w3.org/TR/2010/WD-mediaont-10-20100608
[2] http://www.w3.org/TR/mediaont-10/#d0e5511
[3] http://www.w3.org/TR/mediaont-10/#d0e3064
[4] http://www.w3.org/TR/mediaont-10/#d0e9670
[5] http://lists.w3.org/Archives/Public/public-xg-lld/2010Jul/0075.html
[6] http://www.w3.org/TR/2010/WD-mediaont-api-1.0-20100608/

-- 
Thomas Baker <[log in to unmask]>