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Re: SKOS concept scheme URIs as values for constraints

From: Martynas Jusevičius <martynas@graphity.org>
Date: Fri, 07 Aug 2015 16:55:14 +0000
Message-ID: <CAE35VmwH65jAKu2kMvojomeeOdtC2=Hf9XJ2EsvBfJH3wn7ROg@mail.gmail.com>
To: Arnaud Le Hors <lehors@us.ibm.com>, Holger Knublauch <holger@topquadrant.com>, Phil Archer <phila@w3.org>
Cc: public-data-shapes-wg@w3.org, "public-rdf-shapes@w3.org" <public-rdf-shapes@w3.org>
Phil,

why are you basing your design on the namespace URI? I think a more
semantic way would be to allow all values of ?concept, where ?concept
rdfs:isDefinedBy ?ontology, and ?ontology is the vocabulary you want to use.


Martynas
graphityhq.com

On Fri 7 Aug 2015 at 18:48 Phil Archer <phila@w3.org> wrote:

> Thanks for the replies everyone.
>
> Hmm... templates, special code, DIY... Meh. In short, the use case is
> not covered out of the box.
>
> To be useful, I'd expect the validator to go and fetch the SKOS concept
> scheme and check that the value of a property is valid. So I guess the
> questions would be:
>
> 1. Does the URI given as the value of a property dereference?
> 2. Does the type of that resource match what I expect (is it typed as a
> SKOS Concept in this case).
>
> Of course, that's a heavy burden, I well understand that, and the burden
> may be more than is needed in many cases, and too much in others, but
> authoritative lists of allowed values are not uncommon.
>
> If this is out of scope for the work, OK, that's my answer. If the
> answer is "you can bolt something on the side that does it" then, well,
> I'd likely not bother with the bolt and just do it myself anyway - which
> kind of defeats the object.
>
> Karen's Use Case 37 does indeed seem very similar and, yes, SHACL has
> regEx matching, enumerated lists and so on, so a lot of what I'm asking
> can be done - and that may be sufficient (or that may have to be
> sufficient), but without fetching the authoritative list of allowed
> values from an external source, the issue of synchronising will always
> come up.
>
> I should indeed have some test data imminently, if it's wanted.
>
> Thanks
>
> Phil.
>
> PS. I'm very likely to join the f2f in Lille next month as I'll be
> passing through on my way home from Brussels. Looking forward to
> catching up with the wider work of the group.
>
> On 05/08/2015 01:01, Holger Knublauch wrote:
> > This is correct and thanks for highlighting this. I wanted to be brief
> > and could elaborate or even implement the template as an example. I was
> > hoping that my statement "using a template" would have been sufficiently
> > clear, but maybe it wasn't. Yes, there needs to be at least one person
> > on the planet, knowledgeable of SPARQL and SHACL, who needed this
> > feature to cast it into a template and publish it for everyone else to
> use.
> >
> > (BTW I later noticed that the original requirement may have been about
> > checking for the presence of URIs in a certain named graph. In that
> > case, the SPARQL GRAPH keyword could be used, assuming the named graphs
> > are present in the same dataset, or SERVICE for external graphs. There
> > are all kinds of variations here, which is why my inclination is to
> > leave this as an opportunity for third-party templates, not the core
> > language.)
> >
> > Regards,
> > Holger
> >
> >
> > On 8/5/2015 9:29, Arnaud Le Hors wrote:
> >> Holger,
> >>
> >> I think we ought to clarify that what you present here isn't all it
> >> takes because it relies on having shx:allowedValueNamespaces defined
> >> somewhere, presumably using the SPARQL extension.
> >>
> >> I know you wrote "an end-user syntax" and the implication is that some
> >> advanced-user has defined such a template for the end-user but we need
> >> to be careful not to set the wrong expectation.
> >>
> >> Regards.
> >> --
> >> Arnaud  Le Hors - Senior Technical Staff Member, Open Web Technologies
> >> - IBM Software Group
> >>
> >>
> >> Holger Knublauch <holger@topquadrant.com> wrote on 08/03/2015 03:29:13
> >> PM:
> >>
> >> > From: Holger Knublauch <holger@topquadrant.com>
> >> > To: public-data-shapes-wg@w3.org, "public-rdf-shapes@w3.org"
> >> > <public-rdf-shapes@w3.org>
> >> > Date: 08/03/2015 03:30 PM
> >> > Subject: Re: SKOS concept scheme URIs as values for constraints
> >> >
> >> > This could be represented in SHACL using a template, with an end-user
> >> > syntax such as
> >> >
> >> > ex:MyShape
> >> >      a sh:Shape ;
> >> >      sh:property [
> >> >          a shx:AllowedValueNamespacesConstraint ;
> >> >          sh:predicate ps:siteDesignation ;
> >> >          shx:allowedValueNamespaces (
> >> > "http://inspire.ec.europa.eu/codelist/DesignationValue/" ) ;
> >> >          sh:valueClass skos:Concept ;
> >> >      ] .
> >> >
> >> > In the above scenario I am assuming that the algorithm will check that
> >> > all values of the given property must be URIs starting with one of the
> >> > enumerated strings (using STRSTARTS in SPARQL). It would not go to the
> >> > web to check whether there is actually a Graph at that namespace -
> this
> >> > would be outside of what SPARQL can do right now.
> >> >
> >> > I cannot comment on whether this particular pattern should become part
> >> > of the Core vocabulary too, but the whole point of the extension
> >> > mechanism is to allow anyone to represent and publish their own
> >> favorite
> >> > constraint design patterns, so that they don't rely on the choices
> made
> >> > by a particular working group in the year 2015.
> >> >
> >> > Holger
> >> >
> >> >
> >> >
> >> > On 8/4/2015 5:39, Karen Coyle wrote:
> >> > > Phil,
> >> > >
> >> > > Thanks for bringing this up. I thought that I had covered this in
> use
> >> > > case #34 [1], and at one point I asked if all of these criteria were
> >> > > met by the requirements and I was assured that they were. This is a
> >> > > key use case for the cultural heritage community, so if there are
> any
> >> > > doubts that these requirements can be met we need to address this.
> >> > > Perhaps the was to resolve this is to provide test cases. There seem
> >> > > to be some functional versions of SHACL that could be used to test
> >> > > this, if I'm not mistaken. Would you be able to provide some test
> >> data?
> >> > >
> >> > > Thanks,
> >> > >
> >> > > kc
> >> > > [1]
> >> > > http://w3c.github.io/data-shapes/data-shapes-ucr/#uc37-defining-
> >> > allowed-required-values
> >> > >
> >> > > On 8/3/15 9:48 AM, Phil Archer wrote:
> >> > >> Hi,
> >> > >>
> >> > >> I've had an opportunity to take a look at the SHACL work today and
> I
> >> > >> notice one of the use cases looks set to be missed - although
> >> only just.
> >> > >>
> >> > >> The UCR doc includes the one about self-describing Linked Data
> >> [1] which
> >> > >> talks about the value of a property being a skos:Concept. Are you
> >> > >> considering making this a little tougher, i.e. that the value of
> >> a given
> >> > >> property is a concept defined in a specific scheme?
> >> > >>
> >> > >> I see that SHACL allows the enumeration of values [2], but I want
> >> to be
> >> > >> able to say "any value from the SKOS Concept scheme at <foo>". It
> >> looks
> >> > >> like SHACL won't support that?
> >> > >>
> >> > >> Use Case: INSPIRE
> >> > >>
> >> > >> INSPIRE [0] - the European Union's obligatory set of standards for
> >> > >> environmental and geospatial data - has a handy registry of SKOS
> >> concept
> >> > >> schemes [3]. In one of my projects, I've been working on creating
> >> RDF
> >> > >> vocabularies that are compatible with the INSPIRE data model,
> >> such as
> >> > >> the one about protected sites [4]. That has a property
> >> > >> ps:siteDesignation for which the range is defined as skos:Concept
> >> but
> >> > >> really what it should say is:
> >> > >>
> >> > >> the value of this property should be a skos:Concept in the scheme
> at
> >> > >> http://inspire.ec.europa.eu/codelist/DesignationValue/.
> >> > >>
> >> > >> It would be inappropriate to enumerate the concepts in that concept
> >> > >> scheme (there are 6 of them) since it is under a different
> >> > >> organisation's change control.
> >> > >>
> >> > >> I recognise that this leads to the possibility that a graph that is
> >> > >> valid today may become invalid if the INSPIRE Registry were to be
> >> > >> amended but that's a management task for the European Commission to
> >> > >> worry about (i.e. the people responsible for the INSPIRE data
> >> model) and
> >> > >> they would need to be mindful of such situations which would occur
> >> > >> whether we were talking about RDF graphs or dollops of GML, so I
> >> don't
> >> > >> think that's a show stopper here.
> >> > >>
> >> > >> WDYT?
> >> > >>
> >> > >> Phil.
> >> > >>
> >> > >>
> >> > >> [0] http://inspire.ec.europa.eu/
> >> > >>
> >> > >> [1]
> >> > >> http://w3c.github.io/data-shapes/data-shapes-ucr/#uc28-self-
> >> > describing-linked-data-resources
> >> > >>
> >> > >>
> >> > >>
> >> > >> [2]
> >> > >> http://w3c.github.io/data-shapes/shacl/
> >> > #AbstractAllowedValuesPropertyConstraint
> >> > >>
> >> > >>
> >> > >>
> >> > >> [3] http://inspire.ec.europa.eu/registry/
> >> > >>
> >> > >> [4] http://www.w3.org/2015/03/inspire/ps
> >> > >>
> >> > >>
> >> > >
> >> >
> >> >
> >>
> >
> >
>
> --
>
>
> Phil Archer
> W3C Data Activity Lead
> http://www.w3.org/2013/data/
>
> http://philarcher.org
> +44 (0)7887 767755
> @philarcher1
>
>
Received on Friday, 7 August 2015 16:55:53 UTC

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