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Re: SKOS concept scheme URIs as values for constraints

From: Martynas Jusevičius <martynas@graphity.org>
Date: Fri, 07 Aug 2015 17:02:55 +0000
Message-ID: <CAE35Vmw0qqJuy9zwob1vGrx5DaWcX5PhYjMGOUjBKtWtD9MHdw@mail.gmail.com>
To: Phil Archer <phila@w3.org>, Arnaud Le Hors <lehors@us.ibm.com>, Holger Knublauch <holger@topquadrant.com>
Cc: public-data-shapes-wg@w3.org, "public-rdf-shapes@w3.org" <public-rdf-shapes@w3.org>
Yes, because you cannot assume that concepts at a Linked Data location are
defined by (an ontology served at) that location. They might be served as
RDF there but be defined somewhere else. In general you need to do a lookup
to check that - unless you have the vocabulary cached.
On Fri 7 Aug 2015 at 18:57 Phil Archer <phila@w3.org> wrote:

> OK Martynas, but does that imply the HTTP GET I'm after as well?
>
> On 07/08/2015 17:55, Martynas Jusevičius wrote:
> > 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
> >>
> >>
> >
>
> --
>
>
> 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 17:03:34 UTC

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