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Re: RDF-ISSUE-12 (String Literals): deprecate language tags?

From: Ivan Herman <ivan@w3.org>
Date: Sun, 6 Mar 2011 09:16:15 +0100
Cc: Pat Hayes <phayes@ihmc.us>, RDF Working Group WG <public-rdf-wg@w3.org>
Message-Id: <3F20A39D-DF32-4291-975A-3A9370BBE990@w3.org>
To: Sandro Hawke <sandro@w3.org>

On Mar 6, 2011, at 24:50 , Sandro Hawke wrote:

> On Sat, 2011-03-05 at 09:24 -0600, Pat Hayes wrote:
>> We can allow language tags on xsd:string literals
> 
> How?  I don't think so.  As I recall (from watching the group, not being
> in it like you), that was the constraint that got us into this mess in
> the first place.  The i18n WG said RDF had to have language tags on
> text, and the xsd WG said we couldn't put language tags on datatyped
> values.  So our best option seemed to be to have strings which were not
> datatyped values.
> 
> We could try pushing on those constraints again and see what has
> changed, given years of additional experience.
> 
> My first inclination, in approaching this ISSUE-12, is to first see if
> we can get rid of language-tagged literals.  Are there people who will
> fight to keep them?  If so, please speak up.  

I think I would...

Multilingual vocabularies use them. This is what SKOS advices to use in terms of alternative labels. This is what any dbpedia page use at the moment (see [1]). I am afraid that it would be a problem if, via deprecation, we rendered all this deployment invalid even through the change path you propose below. Besides, the approach you propose below seems to be way more complicated and less 'user-friendly':-(

Indeed, xsd:string (even in its latest not-yet-standard incarnation[2]) does not have a 'slot' for language. But because they are still not-yet-standard, we may go back to them and raise this issue again. Alternatively, we can take rdf:plainLiteral as the core, say that a "abcd" without datatype is to be considered as a syntactic shorthand for an rdf:plainLiteral (ie, deprecate plain literal) and also deprecate the usage of xsd:string in RDF...

Ivan


[1] http://dbpedia.org/data/Amsterdam.n3
[2] http://www.w3.org/TR/xmlschema11-2/#string



> I know a lot has been
> invested in them over the years, but are people happy with the results?
> I genuinely don't know.
> 
> To be a little more detailed, this straw proposal is: 
>    - we weakly deprecate language-tagged literals, saying folks
>      should stop generating them 
>    - we recommend a different way of getting the same functionality that
>      does not require changes to RDF, SPARQL, OWL, etc.
>    - we explain how to map from the old way to the new way, and
>      suggest that software do the conversion, offering higher layers
>      the new style of access, even if data came in "old style".
> 
> There are several "new" ways to go, involving introducing one or more
> new nodes.  So, instead of:
> 
>  db:cat dbo:abstract "The cat (Felis catus), also known as..."@en,
>                      "Le chat domestique (Felis silvestris..."@fr,
>                      ...
> 
> We could instead have the abstract be a single "MultiLanguageString",
> which has versions in various languages, like this:
> 
>  db:cat dbo:abstract [ l:en "The cat (Felis catus), also known as...";
>                        l:fr "Le chat domestique (Felis silvestris..."],
>                      ...
> 
> ... or the abstract could have multiple values, each of which is a
> text-in-some-language, like this:
> 
>  db:cat dbo:abstract [ a l:Text-en; 
>                        l:text "The cat (Felis catus), also known as..."],
>                      [ a l:Text-fr; 
>                        l:text "Le chat domestique (Felis silvestris..."],
>                      ...
> 
> The first option has the advantages of brevity; the second allows more
> extension to many other kinds of annotations on the strings, aside from
> language, like long-version and short-version,
> approved/proposed/deprecated, or whatever.  I suspect it would be hard
> to pick between these two if we had to.
> 
> Personally, I don't have a strong opinion about this issue.  I think
> language tagged literals are an unfortunately design, but I think most
> of the cost of them has already be paid for, and changing at this point
> would probably be more trouble than it's worth.  On the other hand, if
> it turns out folks are mostly avoiding language tagged literals in favor
> of one of the above styles, or something else, I wouldn't mind us
> changing.
> 
>   -- Sandro
> 
> 
> 


----
Ivan Herman, W3C Semantic Web Activity Lead
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Received on Sunday, 6 March 2011 08:14:40 UTC

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