Re: fundamental issues

On 2/16/2015 20:00, Dimitris Kontokostas wrote:
>
>
> On Sat, Feb 14, 2015 at 8:01 PM, Karen Coyle <kcoyle@kcoyle.net 
> <mailto:kcoyle@kcoyle.net>> wrote:
>
>
>
>     On 2/14/15 9:37 AM, Peter F. Patel-Schneider wrote:
>
>             The question is only sensible if one already assumes RDFS
>             or OWL
>             >semantics. Outside of RDFS/OWL semantics, resources can
>             do all these
>             >things without being classes.
>
>         OK, so replace RDF classes with "RDF types in RDF and RDFS
>         classes in
>         RDFS".  The point is whether documents will contain triples
>         that use shapes
>         where there are now RDF type or RDFS classes.
>
>
>
>     If instance data will use shapes where they now use RDF, how would
>     you fulfill the requirements implied in User Story #4 [1] where
>     the same node in a graph can serve multiple roles? Or in general
>     how do you address re-usability of your data in different contexts?
>
>
> Shapes does not solve this problem, maybe postpone it a bit [1] until 
> when/if they get further adopted. In the same way one can use 
> different "shapes" at different contexts, one can use different class 
> constraints at different contexts.
>
> [1] 
> https://lists.w3.org/Archives/Public/public-data-shapes-wg/2015Jan/0198.html

+1 and see also the practice of Partial Imports

     https://www.w3.org/2014/data-shapes/wiki/Partial_Import

which is a simple version of the idea of contexts. While not as powerful 
as constraint-specific contexts, partial imports have the advantage that 
they can completely change the whole class and shape definitions, e.g. 
they can establish different rdfs:subClassOf relationships. This of 
course assumes that not all triples are mixed together into a single 
large graph.

Other approaches to the "different shapes in different contexts" exist, 
including

- inferencing (e.g. use rdfs:subPropertyOf to "merge" related properties)
- mapping (e.g. SPARQL CONSTRUCT transforms/SPINMaps)
- magic properties and on-the-fly transformations

We have successfully used all of the above in several projects.

Holger



>
>     kc
>     [1]
>     https://www.w3.org/2014/data-shapes/wiki/User_Stories#S4:_Issue_repository
>
>     -- 
>     Karen Coyle
>     kcoyle@kcoyle.net <mailto:kcoyle@kcoyle.net> http://kcoyle.net
>     m: 1-510-435-8234
>     skype: kcoylenet/+1-510-984-3600 <tel:%2B1-510-984-3600>
>
>
>
>
> -- 
> Dimitris Kontokostas
> Department of Computer Science, University of Leipzig
> Research Group: http://aksw.org
> Homepage:http://aksw.org/DimitrisKontokostas