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Re: Core or Lite?

From: Arnaud Le Hors <lehors@us.ibm.com>
Date: Tue, 24 Mar 2015 10:12:01 -0700
To: Irene Polikoff <irene@topquadrant.com>
Cc: public-data-shapes-wg@w3.org
Message-ID: <OF6CCBE46E.2C24E163-ON85257E12.005D98FB-88257E12.005E7CC9@us.ibm.com>
Hi Irene,

Thank you for your input. What you're saying is actually very much in line 
with the findings of the workshop. We can define a declarative way that 
will address 80% of use cases and we need an extension mechanism to 
address the remaining 20%.

Am I missing something?
--
Arnaud  Le Hors - Senior Technical Staff Member, Open Web Technologies - 
IBM Software Group




From:   Irene Polikoff <irene@topquadrant.com>
To:     Arnaud Le Hors/Cupertino/IBM@IBMUS, <public-data-shapes-wg@w3.org>
Date:   03/24/2015 09:27 AM
Subject:        Re: Core or Lite?



Majority of our customers end up needing to write some SPARQL-based 
templates for data validation and UI generation. The pre-built constructs 
may cover 80% of their use cases, but 20% still remains. And for some the 
pre-built constructs (and we ship a bit more than what is now in SHACL) 
cover less than 50%. We try to look for commonality and gradually include 
the most common ones as pre-built. But complete coverage is simply not 
possible. Each customer has some uniqueness. Being able to formally define 
their own templates has been pretty critical for these users. Some have 
talked about creating template exchanges where they could share with 
others.

Over the last 10 years of working with customers that use RDF to stand up 
enterprise solutions, we have been in direct communication with hundreds 
if not thousands (some use our products without having any in depth 
interactions with us). These customers span many different industries – 
financial services, pharma and health care, energy, manufacturing, 
government and so on. I am not sure to what extent anyone else on the 
working group has had a similar breadth and depth of experience across the 
number of different customers, applications and industries.

Many of these users have running enterprise systems and their needs are 
important. I believe the fact that the workshop did not receive this input 
shouldn't matter at this point. We are providing it today. Further, this 
working group has moved well beyond the information available during the 
workshop by collecting requirements over the last 6 months. Is there any 
reason we need to go back to the workshop when considering requirements?

Irene

From: Arnaud Le Hors <lehors@us.ibm.com>
Date: Tuesday, March 24, 2015 at 11:51 AM
To: <public-data-shapes-wg@w3.org>
Subject: Re: Core or Lite?
Resent-From: <public-data-shapes-wg@w3.org>
Resent-Date: Tue, 24 Mar 2015 15:57:35 +0000

I think we're touching on the very point of division in the group: whether 
writing complex queries using SPARQL is the normal/common case or not. 
From my point of view the workshop clearly didn't support that point of 
view and this is why the charter is written the way it is.

Participants agreed that we should have a declarative mechanism a la OSLC 
Resource Shapes and, in recognition of the fact that there is only so much 
one can do that way, an extension mechanism should also be available to 
address complex cases which can't be handled declaratively. Here is how 
the report reads (http://www.w3.org/2012/12/rdf-val/report):

There was consensus on the need for 
1.        Declarative definition of the structure of a graph for 
validation and description.
2.        Extensible to address specialized use cases.
3.        A mechanism to associate descriptions with data.

Note that this doesn't mean that the extension mechanism is any less 
normative than the declarative one but it makes a difference as to whether 
the extension mechanism is the center piece (or as Richard put it "the 
most basic construct") or not.
--
Arnaud  Le Hors - Senior Technical Staff Member, Open Web Technologies - 
IBM Software Group


Arthur Ryman <arthur.ryman@gmail.com> wrote on 03/24/2015 05:50:14 AM:

> From: Arthur Ryman <arthur.ryman@gmail.com>
> To: Holger Knublauch <holger@topquadrant.com>
> Cc: "public-data-shapes-wg@w3.org" <public-data-shapes-wg@w3.org>
> Date: 03/24/2015 05:51 AM
> Subject: Re: Core or Lite?
> 
> Holger,
> 
> All aspects of SHACL that are described by the spec are normal in the
> sense that they define compliant behavior. You seem to be implying
> that only Part 1 is normal. I don't understand what is gained by this
> use of the term "normal".
> 
> I'd also like to clarify that I think we only need one RDF namespace.
> Part 1 defines some of the terms and Part 2 defines the rest of the
> terms.
> 
> If we are going to use the term "normal", let's agree on the meaning.
> One meaning is say that the largest user group is the "normal" one. If
> that is the case then we have clear feedback that the majority of
> users will want a high-level vocabulary for expressing common
> constraints. A smaller, more advanced, set of users will write
> constraints in SPARQL, JS, ShEx, etc.
> 
> -- Arthur
> 
> 
> 
> 
> 
> On Tue, Mar 24, 2015 at 1:50 AM, Holger Knublauch
> <holger@topquadrant.com> wrote:
> > On 3/24/2015 15:17, Arnaud Le Hors wrote:
> >
> > Holger,
> > What would constitute the "extension mechanism" in your view then?
> >
> >
> > The macro facility could be regarded as an extension mechanism for the 
core
> > vocabulary. Another extension mechanism is the ability to use other
> > languages such as shx:javaScript. But writing complex queries (e.g. 
using
> > SPARQL) is not an extension mechanism. Also, using pre-defined macros 
from a
> > 3rd party template library is also not an extension. So the headline 
of that
> > Part 2 should reflect this differently. That was all I wanted to point 
out.
> >
> >
> > I have to point out that Arthur's suggestion happens to be very much 
in line
> > with what the charter calls for:
> >
> > An RDF vocabulary, such as Resource Shapes 2.0, for expressing these 
shapes
> > in RDF triples, so they can be stored, queried, analyzed, and 
manipulated
> > with normal RDF tools, with some extensibility mechanism for complex 
use
> > cases.
> >
> > I don't think it helps to ignore that and try to force people into
> > considering what was meant to be an "extensibility mechanism for 
complex use
> > cases" the "completely normal use of SHACL".
> >
> >
> > I stick to my statement that it is a completely normal use of SHACL to
> > include SPARQL queries. It is also completely normal for OWL DL users 
to
> > rely on features outside of OWL Lite. In the draft, SPARQL is part of 
the
> > official spec. For a large class of users, what you call the 
"extensibility
> > mechanism" will even be the main feature of SHACL. This includes 
people who
> > currently use OWL and just want to use SPARQL for the bits that OWL 
cannot
> > express. This is how TQ customers have operated for many years and is 
also
> > the least disruptive path to adoption if we want SHACL to succeed with
> > current semantic web people.
> >
> > What we have right now in the WG is that some people believe they 
don't
> > really need SPARQL support, and that the core features are sufficient 
for
> > most use cases. That's good for them, although not backed by much 
empirical
> > evidence. At this stage we have no idea which features will be most 
widely
> > used. Claiming that feature 1 is more important than feature 2  (and 
call
> > feature 2 just an "extension") is premature and makes it more 
difficult for
> > the supporters of feature 2 to get heard.
> >
> > The wording in the Charter was in retrospect unfortunate but it was
> > difficult to clarify all these nuances in a single short sub-sentence. 
Back
> > then I have been very clear that I will object to any attempts to
> > marginalize the SPARQL support, and I will continue to do this. I hope 
the
> > group respects the point of view of the SPARQL camp in the same way 
that we
> > all respect the point of view of those who don't need really SPARQL 
support.
> > My draft supports both view points.
> >
> > Regards,
> > Holger
> >
> 

Received on Tuesday, 24 March 2015 17:18:15 UTC

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