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

On 2/9/2015 11:22, Karen Coyle wrote:
> So, with this simple example (and note that there are no classes, 
> either explicit or implicit):
>
> http://lccn.loc.gov/75300479
>    dct:title "Moby Dick" ;
>    dct:creator <http://id.loc.gov/authorities/names/n79006936> ;
>    dct:publisher "M. Kennerley" .
>
> Were you suggesting to add the relationship "hasShape" to this graph 
> like this:
>
> http://lccn.loc.gov/75300479
>    ldom:hasShape ex:bookShape ;
>    dct:title "Moby Dick" ;
>    dct:creator <http://id.loc.gov/authorities/names/n79006936> ;
>    dct:publisher "M. Kennerley" .
>
> If so, this still looks to me to be saying that my book has a 
> relationship to a set of constraints.

I would prefer to not make something like ldom:hasShape part of the 
standard. It could become an extension for other platforms such as OSLC, 
via oslc:instanceShape. Indeed it does not need to be asserted as a 
triple at all, and the information which shapes to use could come from 
the outside, e.g. from a ShExC file (that is not even RDF). IMHO the 
standard should only include rules on how rdf:type can be interpreted, 
if present, because this would be the most natural next step in the 
evolution of the semantic web stack. Even in the presence of rdf:type, 
processors may chose to ignore it, but the default interpretation should 
be that if rdf:type is present then the system would look for 
constraints defined for the class.

What I am trying to explain in this thread is that - like a "shape" - a 
class can serve as a set of constraints that are grouped together and 
organized in a subclass/extension relationship. Classes may be defined 
for the single purpose of serving as such a set of constraints, so that 
any resource (such as <http://lccn.loc.gov/75300479>) can be validated 
against that class. The hasShape relationship is a function that tests 
whether the resource fulfills the constraints defined by the class, even 
if it has no rdf:type triple, or even other rdf:type triples.

I cannot comment further on your example because I don't know what 
constraints you want to check, how you want validation to be triggered 
and what ex:bookShape would look like. I'd be happy to work through a 
complete scenario if you can provide enough details.

Holger

Received on Monday, 9 February 2015 01:40:56 UTC