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RE: SKOS concept scheme URIs as values for constraints

From: <Simon.Cox@csiro.au>
Date: Mon, 10 Aug 2015 01:43:24 +0000
To: <martynas@graphity.org>, <lehors@us.ibm.com>, <holger@topquadrant.com>, <phila@w3.org>
CC: <public-data-shapes-wg@w3.org>, <public-rdf-shapes@w3.org>
Message-ID: <2A7346E8D9F62D4CA8D78387173A054A60299994@exmbx04-cdc.nexus.csiro.au>
rdfs:isDefinedBy has inconsistently interpreted semantics. Some like to use it to link to an OWL ontology, some to another kind of document. My observation is that the community is split.

In the case of skos:Concept the native predicate would skos:inScheme.

Simon

From: Martynas Jusevičius [mailto:martynas@graphity.org]
Sent: Saturday, 8 August 2015 2:55 AM
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
Subject: Re: SKOS concept scheme URIs as values for constraints

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<http://graphityhq.com>

On Fri 7 Aug 2015 at 18:48 Phil Archer <phila@w3.org<mailto: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<mailto:holger@topquadrant.com>> wrote on 08/03/2015 03:29:13
>> PM:
>>
>> > From: Holger Knublauch <holger@topquadrant.com<mailto:holger@topquadrant.com>>
>> > To: public-data-shapes-wg@w3.org<mailto:public-data-shapes-wg@w3.org>, "public-rdf-shapes@w3.org<mailto:public-rdf-shapes@w3.org>"
>> > <public-rdf-shapes@w3.org<mailto: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 Monday, 10 August 2015 01:44:10 UTC

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