Re: Indicating Skolem Nodes (was Re: AW: {Disarmed} Re: blank nodes (once again))

David,

are all those metadata necessary at all? After all, the idea starts with bnodes which, by definition, don't have any type of additional information attached to them by default. So why bother about their skolemized version in this respect? My feeling is that if we did some

http://bnode.me/{UUID} (or http://bnode.me#{UUID})

type URI-s, then dereferencing that URI would return something as similar like

"this UUID is for a blank node"

that is it. Ie, a simple PHP program can return a trivial information in, say, turtle, if you dereference that URI. Because it does not generate anything else, that PHP stuff might become dead simple.

I wonder whether a service running that minimal response would still create as big a load as Sandro fears.

Ivan


On Mar 26, 2011, at 19:54 , David Booth wrote:

> On Fri, 2011-03-25 at 23:05 -0500, Pat Hayes wrote:
>> On Mar 25, 2011, at 10:44 PM, David Booth wrote:
>>> Please, at *least* make it dereferenceable to *some* kind of useful
>>> information.
>> 
>> How? These are supposed to be automatically generated and globally
>> unique. Will you have the skolemizing process also generate a web page
>> somewhere, one for each skolem constant? 
> 
> No, you're missing my point.  I'm not talking about millions of
> auto-generated pages.  I'm talking about information about the
> skolomization process *itself*.  In the very least, the URI could point
> to the skolomization *specification* that was followed in generating
> it.  
> 
> Presumably, the entire reason for *standardizing* a way of skolomizing
> bnodes is to permit RDF consumers to syntactically *recognize* those
> URIs as being skolomized bnodes and potentially do something special
> with them.  (Otherwise generators could just use whatever process they
> wanted, and there would be no need for us to discuss it.)  
> 
> Hence, it would be helpful to give the RDF consumer who comes across one
> of these special URIs the *option* of easily derefererencing it to learn
> how it was generated and what information can be reliably concluded
> about it by syntactic inspection.  
> 
> There are many possibilities for what this information might include,
> some of it mentioned already, such as:
> 
> - The fact that this *is* a skolomized bnode URI.
> 
> - The datetime when it was generated.
> 
> - Who generated it.
> 
> - What algorithm was used.
> 
> This is similar to the idea of having an XML namespace document be
> dereferenceable to information about that namespace, although in this
> case the information would be about the URI itself rather than being
> about the thing that it represents semantically in an RDF graph.
> 
> BTW, lest anyone think this would violate the principle of URI opacity
> http://www.w3.org/TR/webarch/#uri-opacity
> it would not, because the whole point is that the information would be
> specifically licensed -- not guessed.
> 
> 
> -- 
> David Booth, Ph.D.
> http://dbooth.org/
> 
> Opinions expressed herein are those of the author and do not necessarily
> reflect those of his employer.
> 
> 


----
Ivan Herman, W3C Semantic Web Activity Lead
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