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Re: Some interesting things that show up when using a reasoner to classify schema.org

From: Simon Spero <sesuncedu@gmail.com>
Date: Thu, 22 Jan 2015 09:23:51 -0500
Message-ID: <CADE8KM5AKru+_dGz8sc1quGq4uQQYsdsUBA+czDQZOG=3jszNw@mail.gmail.com>
To: Martin Hepp <martin.hepp@unibw.de>
Cc: ☮ elf Pavlik ☮ <perpetual-tripper@wwelves.org>, Gregg Kellogg <gregg@greggkellogg.net>, W3C Web Schemas Task Force <public-vocabs@w3.org>
If only some devilishly handsome Englishman were to somehow write a tool
for  mapping from sdo into owl axioms and post some remarks on his
immediately obvious discoveries to a mailing list....
On Jan 22, 2015 6:51 AM, "Martin Hepp" <martin.hepp@unibw.de> wrote:

> Ah! Yes, that is also a viable way, much better than my proposal! The key
> advantage over my proposal is that the Python code for generating the
> documentation does not need to change - rangeIncludes effectively becomes
> rangeHint and domainIncludes domainHint, and the integrity constraint
> axioms will be modeled using rdfs:domain and rdfs:range with complex class
> definitions, as in this example (from GoodRelations):
>
> gr:condition a owl:DatatypeProperty;
>         rdfs:comment "A textual description of the condition of the
> product or service, or the products or services included in the offer (when
> attached to a gr:Offering)"@en;
>         rdfs:domain  [ a owl:Class;
>                                    owl:unionOf (gr:Offering
> gr:ProductOrService) ];
>         rdfs:isDefinedBy <http://purl.org/goodrelations/v1>;
>         rdfs:label "condition (0..1)"@en;
>         rdfs:range rdfs:Literal.
>
> Martin
>
> --------------------------------------------------------
> martin hepp
> e-business & web science research group
> universitaet der bundeswehr muenchen
>
> e-mail:  martin.hepp@unibw.de
> phone:   +49-(0)89-6004-4217
> fax:     +49-(0)89-6004-4620
> www:     http://www.unibw.de/ebusiness/ (group)
>          http://www.heppnetz.de/ (personal)
> skype:   mfhepp
> twitter: mfhepp
>
>
>
>
>
> On 22 Jan 2015, at 12:21, ☮ elf Pavlik ☮ <perpetual-tripper@wwelves.org>
> wrote:
>
> > On 01/22/2015 11:36 AM, Martin Hepp wrote:
> >> Hi elf:
> >>
> >> On 22 Jan 2015, at 11:26, ☮ elf Pavlik ☮ <perpetual-tripper@wwelves.org>
> wrote:
> >>
> >>> On 01/21/2015 05:21 PM, Martin Hepp wrote:
> >>>> Hi Dan,
> >>>> A hands-on solution would be to add two internal "annotation"
> properties "rangeHint" and "domainHint" that allow explicitly triggering
> the display of certain schema.org types in the documentation.
> >>>>
> >>>>
> >>>>   <div typeof="rdf:Property" resource="http://schema.org/purpose">
> >>>> ...
> >>>>     <span>Range: <a property="http://schema.org/rangeHint" href="
> http://schema.org/MedicalDevicePurpose">MedicalDevicePurpose</a></span>
> >>>>     <span>Range: <a property="http://schema.org/rangeIncludes" href="
> http://schema.org/Thing">Thing</a></span>
> >>>>   </div>
> >>>>
> >>>>
> >>>> The documentation could then list the formal range (Thing) and
> popular types for the range (e.g. MedicalDevicePurpose)
> >>>
> >>> http://schema.org/rangeIncludes
> >>> Relates a property to a class that constitutes (one of) the expected
> >>> type(s) for values of the property.
> >>>
> >>> http://schema.org/domainIncludes
> >>> Relates a property to a class that is (one of) the type(s) the property
> >>> is expected to be used on.
> >>>
> >>> AFAIK both of those don't cause any inferences so in a way they already
> >>> act in a similar way to rangeHint and domainHint which you propose.
> >>>
> >>> If rangeIncludes and domainIncludes have some *formal* consequences I
> >>> think they could use bit more of documenting.
> >>> http://schema.org/docs/datamodel.html
> >>
> >> You are right that the documentation does not say so, but I assume the
> Google Structured Data Testing Tool and production systems inside
> Google/Bing/Yahoo/Yandex use rangeIncludes and domainIncludes to assess the
> validity of data.
> >>
> >> The beginning of the discussion was that Simon reported a range of e.g.
> "Place OR Restaurant" as an inconsistency, and I replied that such patterns
> are in use in order to trigger more specific type hints.
> >>
> >> If rangeIncludes and domainIncludes were just for type hints, we would
> not need to fix such domain or range specifications.
> >>
> >> In my understand, rangeIncludes and domainIncludes were introduced in
> order to avoid the unintuitive semantics of domain and range in RDFS and
> OWL, and to be able to list alternative classes without defining a complex
> class that is the union thereof.
> >>>
> >>> BTW James M Snell in Activity Streams 2.0 uses owl:unionOf to specify
> >>> multiple types for domain and range. Maybe (domain/range)Includes could
> >>> act just as hints and schema.org could use something similar for
> >>> expressing *formal* consequences?
> >>
> >> GoodRelations has been using this pattern since ca 2008, too - as a
> means to stay within OWL without triggering unintended additional type
> inferences.
> >>
> >> But still this pattern does not allow giving hints to users on popular
> specializations of the formally defined type or types.
> >
> > I wanted to suggest that - instead of adding yet another informal way of
> > specifying domain and range using *Hint. We could acknowledge current
> > *Includes properties as informal hints intended for broad community of
> > people, who develop various tools for publishing data on the web. Then
> > we can add proper, formal definitions only relevant for much smaller
> > group of developers who work on validators etc. This way we could use
> > more complex constructs from OWL and improve alignment with broader
> > Linked Data ecosystem :)
> >
> >
>
>
>
Received on Thursday, 22 January 2015 14:24:22 UTC

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