Re: please read before participating in translation scheme debate [Re: Translating DB values to RDF terms using 1) R2RML views and 2) using R2RML-native translation scheme]

On 14 Dec 2011, at 20:01, Juan Sequeda wrote:
> Comparing both proposals:
> 
> Souri:
> 
> x:myTranslationScheme rr:translationMap
>   [ rr:toTerm <http://www.nyc.gov> ;            rr:fromTerm <http://www.city.New%20York.NY.us> ] ;
>   [ rr:toTerm <http://www.cityofboston.gov> ;   rr:fromTerm <http://www.city.Boston.MA.us> ] ;
>   [ rr:toTerm <http://www.atlantaga.gov> ;      rr:fromTerm <http://www.city.Atlanta.GA.us> ] ;
>   [ rr:toTerm <http://www.miamigov.com> ;       rr:fromTerm <http://www.city.Miami.FL.us> ] ;
>   [ rr:toTerm <http://www.dallascityhall.com> ; rr:fromTerm <http://www.city.Dallas.TX.us> ] ;
>   [ rr:toTerm <http://www.lacity.org> ;         rr:fromTerm <http://www.city.Los%20Angeles.CA.us> ] ;
>   [ rr:toTerm <http://www.sfgov.org> ;          rr:fromTerm <http://www.city.San%20Francisco.CA.us> ] ;
>   [ rr:toTerm <http://www.seattle.gov> ;        rr:fromTerm <http://www.city.Seattle.WA.us> ] ;
>   [ rr:toTerm <http://www.cityofchicago.org> ;  rr:fromTerm <http://www.city.Chicago.IL.us> ] .
> 
> Richard:
> 
>   []  skos:inScheme x:myTranslationScheme;
>       skos:notation <http://www.city.New%20York.NY.us>;

skos:notation are always literals, so if we want to support IRI-to-something-else mappings with SKOS it would have to be:

      skos:notation "http://www.city.New%20York.NY.us";

The spec would define that skos:notation values must always be literals, regardless of the actual term type (rr:IRI or rr:Literal) that is produced by the term map.

(As I said before, I'm opposed to supporting IRI-to-something-else mappings, because AFAIK the only use case for this are “partial translations” that let untranslated database values pass through unchanged, and I'd rather have such partial translations produce no triples for untranslated database values.)

>       skos:exactMatch <http://www.nyc.gov>.
> 
>   []  skos:inScheme x:myTranslationScheme;
>       skos:notation <http://www.city.Boston.MA.us>;
>       skos:exactMatch <http://www.cityofboston.gov>.
> 
> .....
> 
> So basically
> 
> rr:translationMap ~= skos:inScheme
> rr:fromTerm = skos:notation
> rr:toTerm = skos:exactMatch
> 
> 
> Souri's proposal would avoid the following repetitive triple
> 
> []  skos:inScheme x:myTranslationScheme;

It wouldn't even *avoid* the triple. The triple is still there, it's just written using the convenient comma syntax in Turtle. That syntax allows abbreviation of repetitive triples that have the same s+p but different o, like here:

   :Alice foaf:name "Alice"; foaf:knows :Bob, :Charlie, :Dana, :Ed.

So, Turtle has syntactic sugar for repetitive s+p, but not for repetitive p+o. Therefore, in Souri's proposal it can be abbreviated; in my proposal, where the property points in the other direction, it can't. Unfortunately there is no inverse of skos:inScheme defined in SKOS, so there's no way around that if we want to use SKOS.

> Am I missing something else?

Nope.

Best,
Richard



> 
> 
> 
> Best,
> Richard
>

Received on Wednesday, 14 December 2011 20:21:59 UTC