Re: The need for RDF in Linked Data

On 17 June 2013 07:26, David Booth <david@dbooth.org> wrote:

> There seems to be some persistent misunderstanding about the role of RDF
> in Linked Data, as evidenced by comments like the following:
>
>   "RDF is just one implementation of Linked Data"
>
> If Linked Data is intended to support the goal of the Semantic Web, then
> unless the Semantic Web is re-architected with a new foundation, RDF is
> *essential* to Linked Data -- not optional, and not merely one potential
> choice among many.  the reason is that the Semantic Web critically relies
> on the use of *both* a standard universal identification convention (URIs)
> for its vocabulary, *and* a standard universal information model (RDF) for
> making statements.
>
> To understand why a standard universal information model is important, one
> must think back to the central goal of the Semantic Web.  the goal is to
> enable computers to do more useful things for us: to enable them to find,
> share, combine and make meaningful use of web data.
> http://www.scientificamerican.**com/article.cfm?id=the-**semantic-web<http://www.scientificamerican.com/article.cfm?id=the-semantic-web>
> This means that a client application processing some web data should be
> able to follow links in that data to find more data that it can *also*
> meaningfully use.  the only way that can be achieved is by using a standard
> universal information model.  otherwise the client application will have no
> reliable way to properly interpret that new data.
>
> For example, suppose the client application dereferences a URI and obtains
> a comma-separated-values (CSV) document.  unless the client application
> knew how to interpret that file, it would not be able to make meaningful
> use of that data.  it would be stuck at a dead end.  but if the document
> were expressed in a standard universal information model, then the client
> application would at least be able to understand what statements the
> document was making.  and if the client application did not already
> understand the vocabulary -- i.e. the meanings of the URIs -- then it could
> recursively, using Linked Data techniques, dereference the URIs to discover
> their meanings.
>
> Why does RDF need to be the standard universal information model?  not
> because it is perfect, but because *some* standard universal information
> model is needed, and that is the one that was chosen, just as URIs were
> chosen to be the standard universal identification convention. furthermore,
> because RDF is syntax independent, a document does not have to *look* like
> RDF in order to be interpreted as RDF. for example, GRDDL allows arbitrary
> XML to be interpreted as RDF.  The enormous value of JSON-LD is that it
> provides a more web-developer-friendly syntax than ever before for a
> universal information model.
>
> why couldn't other sufficiently powerful information models achieve the
> same Semantic Web goal just as well, and be used in addition to RDF?
> Because that would fragment the web.  instead of one web we would have many
> webs, each one its own walled garden, and that is not be Semantic Web goal.
>  without a shared information model, client applications would not be able
> to meaningfully combine the data from those walled gardens.
>
> I do not expect anyone to take my word for this. All I ask is that you
> think about it.  Because if you do, the conclusion is unavoidable: if
> Linked Data is going to support the goal of the Semantic Web (without
> re-architecting it), then Linked Data MUST be based on RDF.
>
> this obviously begs the question: *should* Linked Data support the goal of
> the Semantic Web?  that certainly was TimBL's intent when he coined the
> term and wrote his article about it:
> http://www.w3.org/**DesignIssues/LinkedData.html<http://www.w3.org/DesignIssues/LinkedData.html>
> (but I continue to be amazed at how differently different people seem to
> understand that article, so I imagine there would still be some who would
> disagree even with *that* point.)
>
> *I* certainly think that Linked Data should support the goal of the
> Semantic Web.  and I think that JSON-LD -- *because* it will be such a
> web-developer-friendly RDF syntax (assuming a few small issues are
> resolved, so that it really *is* an RDF syntax) -- will be a big step
> forward.
>
> If the term Linked Data is "hijacked" by a broader population to mean
> *any* sort of data that is linked -- not necessarily RDF -- then this will
> be a major loss to the Semantic Web community, because it is very hard to
> come up with simple ways to communicate the essence of the Semantic Web.
>  The Linked Data meme has been extremely helpful.  If the RDF component is
> lost, we will have lost the best meme we have ever had for explaining the
> Semantic Web.
>

Universal does not mean unique.


>
> David
>
>
>