Re: Two Standards ?

My concern is not about personal preferences, but about language(s) that 
end users will actually want to use. We already struggle to understand 
shapes versus classes within the WG. The separation that I propose would 
allow us to write two different primers that will be consistent to 
understand and use.

If the charter does not give us the possibility to define two standards, 
then this becomes a matter of packaging. One approach is to introduce a 
small Abstract Syntax for the commonality between LDOM and ShExC. This 
may include something like the Shape Selectors, but not in RDF but 
"abstract". Another option would be to define a compiler from ShExC into 
LDOM RDF and back (I had proposed that before [1] without getting 
feedback). Both concrete syntaxes could still have a similar name, if 
that helps with the standardization process.

I also assume that WGs are still allowed to slightly diverge from the 
original Charter if they justify their reasons for doing so - at least 
that is what I was told when we wrote the original charter. I believe 
the discussions over the last half year (and potentially another half a 
year well into 2015) provide some of those reasons. Also, producing a 
Compact Syntax has been mentioned in the charter.

Holger

[1] 
https://lists.w3.org/Archives/Public/public-data-shapes-wg/2015Jan/0223.html



On 2/14/15 5:07 AM, Arnaud Le Hors wrote:
> I don't think there is evidence yet that a common solution can't be 
> found. Yesterday's strawpoll tells me there is hope we can find some 
> common ground to build on to produce a standard that we can all live 
> with. This may not be anyone's personal preference but standards are 
> typically not.
>
> It may be that eventually some will seek to define other standards but 
> this won't happen here. Our charter doesn't give us that possibility.
> --
> Arnaud  Le Hors - Senior Technical Staff Member, Open Web Technologies 
> - IBM Software Group
>
>
>
>
> From: Dean Allemang <dallemang@workingontologist.com>
> To: Holger Knublauch <holger@topquadrant.com>
> Cc: RDF Data Shapes Working Group <public-data-shapes-wg@w3.org>
> Date: 02/12/2015 08:08 PM
> Subject: Re: Two Standards ?
> Sent by: deanallemang@gmail.com
> ------------------------------------------------------------------------
>
>
>
> I have been talking about Shapes with my FIBO colleagues - we continue 
> to face the expressivity issues around OWL (role intersections and 
> friendly fire seem to come up a lot for us).  We are moving in to 
> things like SPIN/SWRL, and/or FIBO-RIF(a proposal that I worked on 
> last July that moves everything into a subset of RIF) to solve our 
> expressivity issues.  We are currently going to do all of this in 
> Informative Annexes (as opposed to normative recommendations), because 
> we don't (yet) have a good standard in which to write these things.
>
> An expressive shapes language, based on SPARQL, would satisfy our 
> group's needs quite well.
>
> I wonder a bit about the relationship between the two languages that 
> Holger proposes - is it important that we be able to define how a ShEx 
> shape corresponds to an LDOM definition?  Or are they being used in 
> completely different places?  I guess if we take the XSD/RelaxNG 
> example, there needn't be a deterministic relationship between them.
>
> Looking back, it seems to me that it would have been a good thing if 
> RELAX-NG had been done through the auspices of the W3C instead of 
> OASIS.  As it stands now, it seems as if one has to choose one's 
> standard organization to support one's technology.  If we simply 
> recognize that there could be two different perspectives and develop 
> both standards, we  could actually provide coherent (non-competitive) 
> advice about when each one should be used.  If we don't, and the other 
> perspective has an audience, we'll end up seeing it pursued in some 
> other organization. Ugh.
>
>
> Prima facie, it would seem like we are doubling our work, but I don't 
> think that's the case. As Holger said, each group has done enough work 
> now to write up a coherent spec.  It would actually be *more* work to 
> try to reconcile them into a single Recommendation.
>
>
> This situation seems to me to be a bit different from the profiles of 
> OWL, where we use the same words with different constraints on their 
> usage.  Here, we are solving parallel problems with different 
> mechanisms.  Making two standards, that are well-informed by one 
> another, seems like a good idea to me.
>
>
>
> Dean
>
>
>
>
>
>
> On Thu, Feb 12, 2015 at 7:25 PM, Holger Knublauch 
> <_holger@topquadrant.com_ <mailto:holger@topquadrant.com>> wrote:
> A random thought before the week end:
>
> Can this WG (please!) produce two separate standards?
>
> 1) An RDF vocabulary similar to the original LDOM proposal
> 2) The ShEx Compact Syntax aiming at the data reuse scenarios
>
> We already have RDF Schema. We already have OWL. We would already have 
> a third language (LDOM or whatever). Why not have a forth language?
>
> The situation in very similar to XML Schema vs. DTD. vs RELAX-NG. They 
> all solve similar problems, but from different perspectives.
>
> We are currently trying to mix different paradigms together and risk 
> producing something that nobody will be happy with. People with OO 
> background will wonder what the fuzz is about this parallel structure 
> called "Shapes", raising the implementation costs and creating a mix 
> of parallel semantic webs. And ShEx people don't want to worry about 
> the interactions of the various triple models at all - instead have 
> the ShExC files live outside of the triple store. And that makes sense 
> because even if you introduce ldom:instanceShape to separate shapes 
> from classes, you'd still run into conflicts with other ShEx models 
> that also happen to use ldom:instanceShape. The only proper solution 
> here is to not have triples in the first place.
>
> Another constant source of conflict will be the role of SPARQL. The 
> ShEx camp seems to be more concerned about the balance of expressivity 
> and complexity, while the SPIN camp has plenty of use cases where 
> expressivity is the main concern. Furthermore, a SPIN-like LDOM can 
> more easily be combined with existing RDFS and OWL ontologies, filling 
> gaps in that space.
>
> We have a handful of ShEx supporters in the WG. I am sure they could 
> turn their Member Submission into a formal spec quite rapidly. From an 
> LDOM point of view we have plenty of stuff already implemented, and 
> I'd be happy to wrestle and collaborate with anyone to flesh out the 
> open details. The Requirements document is already being split into 
> "Property constraints" and "Complex constraints", so both camps can 
> harvest from the same catalog of requirements. We can also share test 
> cases and produce a small document explaining how to map from one 
> language to another. But the aforementioned reasons and the endless 
> discussions over the last half a year provide plenty of arguments that 
> justify why the WG chose to create two languages.
>
> Why would this separation of deliverables not work?
>
> Thanks,
> Holger
>
>
>