Re: "shape" as a relationship, not a class

On 2/21/15 1:15 AM, Arthur Ryman wrote:
> Holger Knublauch <holger@topquadrant.com> wrote on 02/08/2015 05:36:32 PM:
>
>> ... I am afraid the distinction
>> between real-world objects and their representation drifts into
>> theoretical realms that nobody outside of the RDF world seems to care
>> about (and rightfully so).

My above statement was in response to a previous statement in the thread 
that

 > It seems to me that the key difference between shapes and classes is
 > exactly this: a shape is information about a graph; a class is
 > information about the RWO.

To highlight why this distinction is problematic, look no further than 
SHACL itself.

     sh:Shape rdf:type rdfs:Class .

     ex:MyShape rdf:type sh:Shape .

Shapes are not RWOs. There are similar examples everywhere.

Should it instead be

     ex:MyShape sh:nodeShape sh:Shape ?

Then, what would sh:Shape be?

     sh:Shape sh:nodeShape sh:Shape ?

Welcome to a parallel semantic web that may become an even smaller niche 
than the current semantic web, and meanwhile confuses newcomers to the 
class-based semantic web even more.

Regards,
Holger


> Holger,
>
> The distinction is important in some cases because if you fail to make the
> distinction, then when you read the RDF, it sounds like nonsense. The
> classic example is the distinction between a person and a user account
> owned by that person. A person is a RWO and should have a URI that is
> different that the user account, which is an information resource (a web
> document).
>
> A web document can have properties such as creator (a person), creation
> date, modification date, etc. It makes sense to say that a user account
> document has a modification date, but it is nonsense to say that the
> person who owns the user account has that modification date (barring
> coincidental plastic surgery on that date). FOAF makes this clear. This
> whole topic is nicely discussed in [1], which is co-authored by your
> newest colleague.
>
> [1] http://www.w3.org/TR/cooluris/
>
>

Received on Friday, 20 February 2015 23:04:43 UTC