I finally managed to write up a rather rambling blog post covering these issues

http://efoundations.typepad.com/efoundations/2011/09/things-their-conceptualisations-skos-foaffocus-modelling-choices.html

Pete

> -----Original Message-----
> From: DCMI Glossary Task Group [mailto:[log in to unmask]]
> On Behalf Of Pete Johnston
> Sent: 22 June 2011 13:30
> To: [log in to unmask]
> Subject: dcterms:language, URIs for languages & the "foaf:focus" question
> 
> Prompted by answering a query about URIs for languages (and this is actually
> an issue which I've wrangled with myself in some recent projects)...
> 
> DCMI says the range of the dcterms:language property is the class
> dcterms:LinguisticSystem
> 
> In the examples at
> 
> http://wiki.dublincore.org/index.php/User_Guide/Publishing_Metadata#dct
> erms:language
> 
> we have examples of lexvo.org URIs like
> 
> http://www.lexvo.org/page/iso639-3/eng
> 
> for individual languages
> 
> <aside>
> Oh, actually, I've just noticed a problem there that wasn't what I intended to
> comment on. That is actually the URI of the document which describes the
> language; the URI of the language itself is
> 
> http://lexvo.org/id/iso639-3/eng
> 
> So basically all those examples need to use the http://lexvo.org/id/iso639-
> 3/{tag} pattern.
> </aside>
> 
> So lets assume those examples are corrected. We have
> 
> ex:myBook  dcterms:language <http://lexvo.org/id/iso639-3/eng> .
> 
> And lexvo.org tells me that
> 
> <http://lexvo.org/id/iso639-3/eng> a lvont:Language .
> 
> And that class
> 
> <http://lexvo.org/ontology#Language> rdfs:subClassOf
> dcterms:LinguisticSystem .
> 
> So it's all good, as they say: both lexvo.org and DCMI say that the thing is an
> instance of dcterms:LinguisticSystem.
> 
> The question I was asked (and had asked myself earlier) was
> 
> What about the LoC URIs like http://id.loc.gov/vocabulary/iso639-2/eng ?
> Can I say
> 
> ex:myBook  dcterms:language <http://id.loc.gov/vocabulary/iso639-2/eng> .
> 
> Looking at what LoC says about http://id.loc.gov/vocabulary/iso639-2/eng it's
> an skos:Concept but AFAICT there is no information about any relationship
> with the dcterms:LinguisticSystem class.
> 
> Now, I _think_ the intent is that these URIs are usable directly with
> dcterms:language (as above). That would be "saying" the thing identified by
> that URI is both an skos:Concept (from what LoC say) and a
> dcterms:LinguisticSystem (from what DCMI say about dcterms:language).
> And that seems fine: a Linguistic System is a "conceptual thing".
> 
> An alternative perspective would be that the thing defined by LoC is not itself
> a Linguistic System but a concept which in some way "relates to"/"refers to"
> a Linguistic System as a distinct entity i.e. what I tend to think of as the
> "foaf:focus" case
> 
> http://xmlns.com/foaf/spec/#term_focus
> 
> (It's probably a bit easier to think of the example of an entry for, say, a place,
> where LCSH says that the LCSH entry for Africa
> 
> http://id.loc.gov/authorities/sh85001531#concept
> 
> was created in 1986 and modified in 1999, but that wouldn't apply to the
> actual physical continent itself - so foaf:focus allows you to treat them as two
> distinct things and make a foaf:focus relation between the two)
> 
> Applying this model to the language case, then, there might - I'm only saying
> "might"! - be an argument that it would then be better to say
> 
> ex:myBook  dcterms:language <some-other-uri> .
> 
> <http://id.loc.gov/vocabulary/iso639-2/eng> foaf:focus <some-other-uri> .
> 
> (and that some-other-uri could be a lexvo.org URI)
> 
> I must admit that this seems to me to be making things rather more
> subtle/complex than necessary!
> 
> But either way, I can see that this is almost certainly going to be an FAQ, and I
> think it might be good to
> 
> (a) try and get some guidance from LoC on their intent - essentially: is it OK to
> say http://id.loc.gov/vocabulary/iso639-2/eng is a dcterms:LinguisticSystem?
> (b) based on that answer, include some explicit examples of using the
> id.loc.gov URIs alongside the lexvo.org URIs in our docs
> 
> Pete
> 
> Pete Johnston
> Technical Researcher
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