[Crm-sig] RDFS, XML and more

Pavlos Fafalios fafalios at ics.forth.gr
Fri Sep 10 11:20:36 EEST 2021


Dear all,

Thank you for the interesting discussion. A notice that might be important:

In 'OWL Full', which was designed to allow flexibility and preserve
compatibility with RDFS: *"object properties and datatype properties are
not disjoint"* and *"datatype properties are effectively a subclass of
object properties"*, see:

https://www.w3.org/TR/owl-ref/#OWLFull   (not sure if there is a change on
this in OWL 2)

On the downside, as also described in the above link, the OWL Full features
means that one loses some guarantees that OWL DL and OWL Lite can provide
for reasoning systems.

So, we can have an RDFS implementation that includes the superproperty hack
(and which seems compatible with OWL Full, allowing for some basic
reasoning). And then focus on having an OWL DL implementation (Mark's
effort) which is more strict, provides guarantees and will be useful for
advanced reasoning engines (this implementation can include the property
chain axiom).

Best regards,
Pavlos

On Fri, Sep 10, 2021 at 12:08 AM Robert Sanderson via Crm-sig <
crm-sig at ics.forth.gr> wrote:

>
> Thanks Martin :)
>
> As Francesco asked and Thomas answered, I would also recommend a property
> chain axiom that says:
>
> If: x rdfs:label y
> then: x P1_is_identified_by z ; z a E41_Appellation ,
> P190_has_symbolic_content y .
>
> I quickly defer to those who do OWL more often than I, but I think it's as
> easy as:
>
>     rdfs:label owl:propertyChainAxiom (crm:P1_is_identified_by,
> crm:P190_has_symbolic_content) .
>
> Rob
>
>
> On Thu, Sep 9, 2021 at 4:18 PM Martin Doerr <martin at ics.forth.gr> wrote:
>
>> Sorry, I just forgot:
>>
>> Of course we can provide guidelines and S/W how to query all names etc.
>> We can hardly forbid CRM users to put appellations into rdfs:label.
>>
>> So, how do this problem solved in OWL? Those of you opposing to the
>> superproperty hack, how do you solve the query question?
>>
>> Best,
>>
>> Martin
>>
>> On 9/9/2021 11:12 PM, Martin Doerr wrote:
>> > Dear Robert, Mark,
>> >
>> > Of course this is not elegant schema design. Unease is accepted, but
>> > what are the alternatives??
>> >
>> > On 9/9/2021 10:30 PM, Robert Sanderson wrote:
>> >>
>> >>
>> >>
>> >> As expected, it entails the nonsense that the literal "fish"@en is an
>> >> E1, E41, E90, etc. which is garbage caused by this pollution in the
>> >> ontology, as literals cannot be the subject of triples.
>> > This is, in my eyes, not nonsense, but simply reality. The literal
>> > "fish" is used as a name. Hence it is ontologically an E41. Following
>> > the definition of E90, "fish"@en is also symbolic object, regardless
>> > whether one distinguishes data objects and literals. Note, that the
>> > definitions of the CRM are ontological, not syntactic in the first
>> place.
>> >
>> > This is a classical problem of data integration, and why formal
>> > ontologies were invented. Literature in the 1980ties discussed that
>> > classes can be hidden in boolean values, strings, or be explicit
>> > tables. There is an arbitrary decision of applications to name things
>> > via labels, or via classes in RDF/OWL. SKOS exclusively names things
>> > via labels.
>> >
>> > So, if one makes a knowledge base that commits to the CRM, I would
>> > like to have a query that returns all names in the whole world I can
>> > reach, regardless what encoding variant and KR paradigm is used.
>> > Otherwise, SKOS names will not be appellations.
>> >
>> > Alternatively, we close our eyes, and hard code in data entry and
>> > query that "fish" is used as Appellation, but just don't write it down.
>> >
>> > @en actually is equivalent to "has language" etc. With these hidden
>> > properties RDFS itself violates the separation of Literals and data
>> > objects.  It opens up a whole world of user-defined data objects
>> > within Literals, with no logical connection to the data objects. This
>> > is nothing than a bad later patch to a problem not initially
>> > anticipated. How are these compatible with OWL reasoners?
>> >
>> > There is no elegant solution to providing an ontology that describes a
>> > reality based on FOL to fitting it exactly with Schema languages.
>> >
>> > At least, this is how I perceive this problem, having seen enough
>> > knowledge representation languages and information integration
>> > literature from the eighties and implementations from the nineties on.
>> >
>> > For me, the question is completely practical: We have a CRM compatible
>> > KB, a real platform. What is the simplest form that I get all names in
>> > the KB back?  I have not seen a whole "RDF" world that my statement
>> > label IsA P1 would turn upside down. Do you have one?
>> >
>> > Best,
>> >
>> > Martin
>> >>
>> >> Hope that helps explain my unease!
>> >>
>> >> Rob
>> >>
>> >
>>
>>
>> --
>> ------------------------------------
>>   Dr. Martin Doerr
>>
>>   Honorary Head of the
>>   Center for Cultural Informatics
>>
>>   Information Systems Laboratory
>>   Institute of Computer Science
>>   Foundation for Research and Technology - Hellas (FORTH)
>>
>>   N.Plastira 100, Vassilika Vouton,
>>   GR70013 Heraklion,Crete,Greece
>>
>>   Vox:+30(2810)391625
>>   Email: martin at ics.forth.gr
>>   Web-site: http://www.ics.forth.gr/isl
>>
>>
>
> --
> Rob Sanderson
> Director for Cultural Heritage Metadata
> Yale University
> _______________________________________________
> Crm-sig mailing list
> Crm-sig at ics.forth.gr
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>


-- 
Dr. Pavlos Fafalios
Postdoctoral research fellow
Project ReKnow <https://reknow.ics.forth.gr/> (MSCA Individual Fellowship)

Centre for Cultural Informatics / Information Systems Laboratory
Institute of Computer Science (ICS)
Foundation for Research and Technology (FORTH)
   and
Visiting Lecturer
Department of Management Science & Technology (MST),
Hellenic Mediterranean University (HMU)

Address: N. Plastira 100, Vassilika Vouton, 70013 Heraklion, Greece
Email: fafalios at ics.forth.gr
Tel: +30-2810-391619
Web: http://users.ics.forth.gr/~fafalios/
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