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Re: best practice property to use for naming a skos:ConceptScheme

From: Bernard Vatant <bernard.vatant@mondeca.com>
Date: Wed, 16 Mar 2011 23:17:02 +0100
Message-ID: <AANLkTi=P0Hg7uDTk4OX+vb8cZP=DPQEYE0CzfyjMgTyR@mail.gmail.com>
To: Thomas Baker <tbaker@tbaker.de>
Cc: Alistair Miles <alimanfoo@googlemail.com>, Simon Reinhardt <simon.reinhardt@koeln.de>, Bob DuCharme <bob@snee.com>, SKOS <public-esw-thes@w3.org>, Pierre-Yves Vandenbussche <pierre-yves.vandenbussche@mondeca.com>
Hello all

For what is worth, among the 85 "linked open vocabularies" we have started
to gather at [1], more than a half (46) use dc: namespace for their
metadata, and 47 rely on dcterms: (for metadata, or otherwise).
And singularly dc:title seems to keep a great popularity among RDF
vocabularies creators :)

BTW stay tuned at [1], for which new interface features are currently
polished at Mondeca Labs and should be announced soon.

[1] http://labs.mondeca.com/dataset/lov

2011/3/16 Thomas Baker <tbaker@tbaker.de>

> On Wed, Mar 16, 2011 at 11:18:45AM +0000, Alistair Miles wrote:
> > > Doesn't answer your question, but:
> > > The DC terms namespace contains all the elements properties, so
> http://purl.org/dc/terms/title exists:
> > > http://dublincore.org/documents/dcmi-terms/#terms-title
> >
> > AFAIK all the properties from the dc elements namespace have been
> "copied"
> > into the dc terms namespace. I believe the main reason for doing this was
> > to allow domains and ranges to be defined on the properties in the dc
> terms
> > namespace. E.g., dcterms:title has range rdfs:Literal, and dcterms:author
> has
> > range dcterms:Actor. I think the hope was to support more consistent
> usage of
> > properties like dcterms:author (usage of
> http://purl.org/dc/elements/1.1/author
> > is highly variable, and many people will put literals in the object
> position).
> >
> > So if you're doing RDF, the http://purl.org/dc/elements/1.1/ namespace
> is
> > effectively deprecated, use http://purl.org/dc/terms/ instead. If you
> want
> > to know more, Tom Baker is the man to ask.
>
> Thank you for the good summary, Alistair!
> (Note: s/author/creator/, s/Actor/Agent/)
>
> This question will be at the top of a revamped FAQ, as it keeps
> coming up, and in many contexts.  Two years ago on this very list,
> I wrote [1]:
>
>    DCMI has gotten alot of positive feedback from the Semantic Web
>    community on the "makeover" of DCMI properties with domains and
>    ranges.  A longer explanation, with historical context:
>
>    dc:title [1] and dc:subject [2] (and the other thirteen Dublin
>    Core properties) were among the first RDF properties declared
>    anywhere.  They were declared as RDF properties before W3C
>    standardized the notion of "range" in the RDF Schema
>    specification.
>
>    As RDF matured, the DC properties became criticized in SW
>    circles for being underspecified.  DCMI wanted to assign ranges,
>    but in doing so did not want to "break" existing legacy data,
>    which used "subject" (for example) both with literal and
>    non-literal values.
>
>    As described in [4, paragraphs starting "Formal domains..."],
>    DCMI resolved this dilemma by creating fifteen properties in the
>    /terms/ namespace in parallel to the corresponding terms in the
>    /elements/1.1/ namespace, and declared the former as
>    subproperties of the latter.
>
>    It is not actually incorrect to continue using dc:subject and
>    dc:title -- alot of Semantic Web data still does -- and since
>    the range of those properties is unspecified, it is not actually
>    incorrect to use (for example) dc:subject with a _literal_ value
>    or dc:title with a _non-literal_ value.  However, good Semantic
>    Web practice is to use properties consistently in accordance
>    with formal ranges, so implementers are encouraged to use the
>    more precisely defined dcterms: properties.
>
>    Tom (wearing his DCMI hat)
>
>    [1] http://dublincore.org/documents/dcmi-terms/#elements-title
>    [2] http://dublincore.org/documents/dcmi-terms/#elements-subject
>    [3] http://dublincore.org/documents/dcmi-terms/#H1
>    [4] http://dublincore.org/documents/dcmi-terms/#terms-subject
>    [5] http://lists.w3.org/Archives/Public/public-swd-wg/2009Jan/0000.html
>
> Tom
>
> [1] http://lists.w3.org/Archives/Public/public-esw-thes/2009Jun/0017.html
>
> --
> Tom Baker <tbaker@tbaker.de>
>
>


-- 
Bernard Vatant
Senior Consultant
Vocabulary & Data Engineering
Tel:       +33 (0) 971 488 459
Mail:     bernard.vatant@mondeca.com
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Mondeca
3, cité Nollez 75018 Paris France
Web:    http://www.mondeca.com
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Received on Wednesday, 16 March 2011 22:17:35 GMT

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