[whatwg] What RDF does Re: Trying to work out...

[Charles McCathieNevile]

On Fri, 09 Jan 2009 12:54:08 +1100, Calogero Alex Baldacchino  
<alex.baldacchino at email.it> wrote:

> I admit I'm not very expert in RDF use, thus I have a few questions.  
> Specifically, maybe I can guess the advantages when using the same  
> (carefully modelled, and well-known) vocabulary/ies; but when two  
> organizations develop their own vocabularies, similar yet different, to  
> model the same kind of informations, is merging of data enough? Can a  
> processor give more than a collection of triples, to be then interpreted  
> basing on knowledge on the used vocabulary/ies?

RDF consists of several parts. One of the key parts explains how to make  
an RDF vocabulary self-describing in terms of other vocabularies.

>  I mean, I assume my tools can extract RDF(a) data from whatever  
> document, but my query interface is based on my own vocabulary: when I  
> merge informations from an external vocabulary, do I need to translate  
> one vocabulary to the other (or at least to modify the query backend, so  
> that certain curies are recognized as representing the same concepts -  
> e.g. to tell my software that 'foaf:name' and 'ex:someone' are  
> equivalent, for my purposes)? If so, merging data might be the minor  
> part of the work I need to do, with respect to non-RDF(a) metadata (that  
> is, I'd have tools to extract and merge data anyway, and once I  
> translated external metadata to my format, I could use my own tools to  
> merge data), specially if the same model is used both by mine and an  
> external organization (therefore requiring an easier translation).

If a vocabulary is described, then you can do an automated translation  
 from one RDF vocabulary to another by using your original query based in  
your original vocabulary. This is one of the strengths of RDF.

>  Thus, I'm thinking the most valuable benefit of using RDF/RDFa is the  
> sureness that both parties are using the very same data model, despite  
> the possible use of different vocabularies -- it seems to me that the  
> concept of triples consisting of a subject, a predicate and an object is  
> somehow similar to a many-to-many association in a database, whereas one  
> might prefer a one-to-many approach - though, the former might be a  
> natural choice to model data which are usually sparse, as in a document  
> prose.

I don't see the ananlogy, but yes, I think the big benefit is being able  
to ensure that you know the data model without knowing the vocabulary a  
priori - since this is sufficient to automate the process of merging data  
into your model.

cheers

Chaals

-- 
Charles McCathieNevile  Opera Software, Standards Group
     je parle français -- hablo español -- jeg lærer norsk
http://my.opera.com/chaals       Try Opera: http://www.opera.com