ISSUE-23: SHACL is already a modeling language

During yesterday's discussions, several people agreed that the real 
topic behind ISSUE-23 ("classes vs shapes") is that some members believe 
that the WG should not produce a competitor to already established W3C 
modeling languages. We believe the WG has already "failed" on this 
respect, because SHACL can already be used as a modeling language.

Instead of using classes, people can use shapes (with sh:scopeClass). 
Instead of defining OWL restrictions, people can use property 
constraints. Ranges have become sh:datatype and sh:class. The syntax of 
SHACL only spells out a different way of how most people interpret OWL 
anyway. There is an almost one-to-one mapping between OWL and SHACL 
features.

By actively blocking a realistic bridge between those two worlds, the 
SHACL community risks producing two unconnected silos. At TopQuadrant we 
would like to promote an evolutionary strategy in which existing RDFS 
and OWL ontologies can be expanded to be also meaningful for 
closed-world constraint checking. The choice between using 
owl:Restriction or sh:property (or both!) should be left to the user 
community, and not be pre-determined by a handful of people who believe 
they can predict the future from their little WG. The approach of 
attaching constraints to classes has already been successfully explored 
in SPIN. It is perfectly fine to combine the inferencing role of OWL 
with the constraint checking role of SHACL into the same models.

I consider this topic absolutely mission-critical for SHACL. I 
appreciate that those who have no strong opinion at least not block the 
view point of TopQuadrant and many of our customers.

Thanks,
Holger

PS: At some stage we had discussed to produce a document to compare the 
roles of SHACL and OWL. What ever happened to that? Without answering 
what a modeling language really is, we should not close ISSUE-23.

Received on Thursday, 17 December 2015 07:33:07 UTC