Re: Validation and cool URIs

Hi Bernard,

I very much second your view point. If we want to be based on RDF, then 
we should honor its basic principles. One of those principles is that of 
self-describing data, where applications can look up the definition of a 
resource by resolving URIs. For example, if a resource declares an 
rdf:type, then an application should be able to look up the definition 
of the class, including its semantic declarations and constraints. This 
should be the default assumption: someone creates an ontology and when 
he publishes it on the web then anyone who wants to reuse that ontology 
should honor the same constraints.

Having said this, applications may overload the default behavior. In 
TopBraid we do this by first looking at local files for the same URI, 
and preferring those over the files from the web. This also makes it 
possible to refer to graphs that do not even exist on the web.

What I haven't understood yet is how those principles are supposed to 
work in the original two Shapes submissions, where resources do not even 
have to have an rdf:type - how is this going to be self-describing data? 
What is the entry point into the validation?

Thanks,
Holger



On 8/4/14, 7:19 PM, Bernard Vatant wrote:
> Peter
>
> 2014-08-01 16:44 GMT+02:00 Patel-Schneider, Peter 
> <Peter.Patel-Schneider@nuance.com 
> <mailto:Peter.Patel-Schneider@nuance.com>>:
>
>     I don't understand.  Is it a good thing that RDF uses URIs or a
>     bad thing?
>
>
> RDF using URIs is a state of affairs, like birds wearing feathers, and 
> apples growing on apple-trees. Wondering if it's good or bad is 
> pointless, but you can't ignore it.
>
> RDF in its philosophy and principles is not separable from the Web 
> architecture, which should allow anyone to figure what one commits to 
> when using a URI. The same URI can be used with different semantics 
> and different logics, defined by different documents, of course, which 
> makes already difficult to figure if the usage is twisting or not the 
> original declared semantics (and agreed, this is an issue with any 
> language, formal or not, there is the authority definition and the 
> real usage) . Is the main focus of RDF validation seems to be contexts 
> where such documents are known only by applications not connected with 
> the Web, hence not accessible from the URIs they use, as the one 
> presented today by Holger [1]? I have nothing against that, we've been 
> doing it also in Mondeca for more than ten years, using URIs under the 
> hood of applications with specific operational semantics, but actually 
> I've always felt uneasy about it, because that does not seem to be a 
> cool way to use URIs [2].
>
> My hope is that this group will clarify this tension between the use 
> of URIs on the Web and in closed environments, and not blur the 
> landscape even more.
>
> [1] 
> http://lists.w3.org/Archives/Public/public-rdf-shapes/2014Aug/0040.html
> [2] http://www.w3.org/TR/cooluris/
>
>
>
>