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Re: Proposed change to the charter, section 4. Deliverables, Recommendation Track

From: Eric Prud'hommeaux <eric@w3.org>
Date: Thu, 7 Aug 2014 20:24:17 -0400
Message-ID: <CANfjZH1gFUDqBCQToo4PJt=wrizxs3+EaXuf+w61PVbZ2_9-Yg@mail.gmail.com>
To: Peter Patel-Schneider <pfpschneider@gmail.com>
Cc: public-rdf-shapes@w3.org, Holger Knublauch <holger@topquadrant.com>
On Aug 7, 2014 12:44 AM, "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
wrote:
>
> Well, I did present what I thought was a good neutral set of
deliverables, namely
>
>
> 1. A syntax and semantics for shapes specifying how to construct shape
> expressions and how shape expressions are evaluated against RDF graphs.
>
> 2. An RDF vocabulary for expressing these shapes in RDF triples, so they
can
> be stored, queried, analyzed, and manipulated with normal RDF tools.
>
> 3. OPTIONAL A specification of how shape verification interacts with
> inference.

I think this one feel off radar. Did you see any support for this?

> 4. OPTIONAL A compact, human-readable syntax for expressing shapes.
>
> peter
>
>
>
>
> On 08/03/2014 03:57 PM, Holger Knublauch wrote:
>>
>> Hi Peter,
>>
>> this mailing list provides plenty of evidence that OWL is not expressive
>> enough and something on the level of SPARQL is needed. ShEx has an escape
>> mechanism to fall back to SPARQL [1], and IBM has explicitly stated that
this
>> is required too [2]. OWL cannot even do basic math or string operations,
>> neither does it have a concept of "variables" that is very much needed
to do
>> complex joins. So as a minimum, the outcome of this group should be to
agree
>> on a high-level vocabulary (possibly OWL and/or Shapes) plus a mechanism
to
>> represent other cases with something like SPARQL. Do you agree so far?
>>
>> Yes, OWL does have a very large overlap with the Shapes that were
originally
>> submitted (mainly cardinalities and ranges). So it is a valid question
whether
>> both are needed. But if you look at the SPIN specification you may
notice that
>> once you have a mechanism such as SPIN (with templates) in place, it
becomes
>> quite trivial to add any number of libraries including the "Shapes"
>> implementation that I presented a while ago [3]. And this library can
cover
>> many more use cases than either the current Shapes proposals nor OWL
closed
>> world can represent, see for example [4] and [5]. Could you clarify
whether
>> your goal is to prevent "Shapes" becoming a standard and use OWL instead?
>>
>> I believe it is easy to just say no to everything. Have you worked out a
>> better proposal? How should the charter look like from your point of
view?
>>
>> Thanks
>> Holger
>>
>>
>> [1] http://www.w3.org/Submission/shex-primer/#semact
>> [2]
http://lists.w3.org/Archives/Public/public-rdf-shapes/2014Jul/0246.html
>> [3]
http://lists.w3.org/Archives/Public/public-rdf-shapes/2014Jul/0237.html
>> [4] http://semwebquality.org/mediawiki/index.php?title=SemWebQuality.org
>> [5]
http://lists.w3.org/Archives/Public/public-rdf-shapes/2014Aug/0040.html
>>
>>
>> On 8/4/2014 3:33, Peter F. Patel-Schneider wrote:
>>>
>>> I do not support this approach at this time.  To me it looks too much
like
>>> having two standards for the same thing.  I feel that the SPARQL-based
>>> approach and the model-checking approach (which is what OWL+CWA boils
down
>>> to for RDF graphs) have quite a large overlap in their capabilities,
even
>>> though they may look quite different technically.
>>>
>>> It may be that I am wrong in this, of course, and that there are good
>>> reasons to split in this way.
>>>
>>>
>>> peter
>>>
>>>
>>> On 08/02/2014 11:21 PM, Holger Knublauch wrote:
>>>>
>>>> A pragmatic proposal: I do believe there is consensus that this WG can
>>>> potentially create some useful and relevant output that could lead to
broader
>>>> use cases for semantic web technology as a whole. There are several
proposals
>>>> on the table that are potentially complementary to each other.
Assuming there
>>>> are enough people who actually sign up for the work, why not produce
multiple
>>>> deliverables that cover more use cases?
>>>>
>>>> 1) Shapes + SPIN, with an explicit mandate to have semantics that are
>>>> executable by SPARQL engines, from day one. The alternative would be
ShEx and
>>>> this could be figured out in the beginning of the WG. This deliverable
would
>>>> be like an extension to SPARQL.
>>>>
>>>> plus
>>>>
>>>> 2) OWL closed world semantics, so that existing OWL ontologies can be
reused.
>>>> This deliverable would basically be an "appendix" to the OWL 2 spec.
>>>>
>>>> This would allow the interest groups to stay on their home turf without
>>>> blocking each other, because blocking each other would be the worst
outcome of
>>>> all. I see no technical difficulties with such as stack, because these
>>>> technologies are complementary to each other: we use OWL closed world
+ SPIN
>>>> all the time, and it works well in practice. In fact I believe both
>>>> specifications have a good and stable starting point so that we could
proceed
>>>> with the process very swiftly.
>>>>
>>>> Peter, would this be an acceptable direction for you?
>>>>
>>>> Thanks,
>>>> Holger
>>>>
>>
>>
>
Received on Friday, 8 August 2014 00:24:46 UTC

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