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Reminder of the workshop and its outcome

From: Arnaud Le Hors <lehors@us.ibm.com>
Date: Tue, 22 Jul 2014 16:28:59 +0200
To: public-rdf-shapes@w3.org
Message-ID: <OFD0511F65.F3C57CFA-ONC1257D1D.004C839F-C1257D1D.004F8E90@us.ibm.com>
Hi all,

I've been on vacation and haven't had a chance to follow the discussion in 
details but I'm a bit surprised by the way the discussion is going. We 
seem to have lost sight of the fact that the proposed charter was drafted 
based on the outcome of the workshop that took place last year and 
provided for a direction to follow.

With that in mind, on behalf of the chairs of the workshop, I'd like to 
remind everyone that:

TopQuadrant was invited to present at the workshop.

During the workshop, Guoqian Jiang (Mayo) presented SPIN (with SPARQL 
queries, as it was in the Member Submission):
    
http://www.w3.org/2001/sw/wiki/images/d/d6/RDF-Validation-Workshop-GJiang-v1.0.pdf 
14-17

The workshop participants found this good for enforcement but not 
high-enough level for definition, like SPARQL.

SPIN apparently has a more declarative representation, but that makes it 
basically like Application Profiles and Resource Shapes
    
http://lists.w3.org/Archives/Public/public-rdf-shapes/2014Jul/0018.html

ShEx is an extension of Resource Shapes to provide disjunction, grouping 
and semantic actions.

ShExC is a human-facing schema language (like RNG Compact Syntax) 
capturing the ShEx expressivity in a much smaller syntax. Compare the ~20 
lines of ShExC to the hundreds in <
http://lists.w3.org/Archives/Public/public-rdf-shapes/2014Jul/att-0002/sotaspin-text.spin.ttl
>.

Independently of the shortcomings one may find in ShEx which I would 
expect a WG to discuss and address as necessary, I would like to point out 
that although the crux of the discussion has focused on validation, the 
workshop made it very clear that the need wasn't simply about validation 
but also about definition/description - as in describing the data a 
specific service can receive. Solutions that may be perfectly suitable for 
validation aren't necessarily as suitable for description. The workshop 
concluded with:

The participants agreed that the W3C should launch an activity to develop 
a human and machine-readable description of the "shape" of the RDF graphs 
that a service produces or consumes. This description should be usable for 
validation, form-generation, as well as human-readable documentation. The 
participants further agreed that the solution must provide a declarative 
way of describing simple integrity constraints along with an extension 
mechanism that allows using technologies such as SPARQL to specify more 
complex constraints. 

Participants had the opportunity to agree to standardize SPIN or CIV. 
That's not what they thought the W3C should do.

Note that this isn't to say that ShEx is necessary the perfect answer but 
I don't think it is very productive to ignore past discussions and 
agreements. Any counter proposal should be positioned with regard to the 
outcome of the workshop.

Best regards.
--
Arnaud  Le Hors - Software Standards Architect - IBM Software Group
Received on Tuesday, 22 July 2014 14:29:37 UTC

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