Re: Terminology: How to call "IRI or blank node"?

No, we definitely do not have any story that is even vaguely related to this 
issue.

Story S1 
https://www.w3.org/2014/data-shapes/wiki/User_Stories#S1:_The_model.27s_Broken.21 
is instead about missing information in an RDF graph that defines an ontology.

peter


On 12/20/2014 07:51 AM, Karen Coyle wrote:
> As we are here defining requirements that meet actual needs, don't we now have
> a requirement to include in the shapes or validation solution the ability to
> define an object type that excludes literal values? (Assuming others also find
> this requirement compelling.) Later we can determine whether/how that can be
> done. If it cannot be done with RDF, then I would hope that actual user needs
> are taken into account in RDF development, which I assume is not frozen at
> this point in time. If it cannot be done with RDF now or ever, then we are
> back to "The Model's Broken!" which is already one of our stories.
>
> kc
>
> On 12/20/14 7:12 AM, Peter F. Patel-Schneider wrote:
>>
>>
>> On 12/19/2014 11:36 PM, Holger Knublauch wrote:
>>>
>>> On 12/20/14, 4:33 PM, Eric Prud'hommeaux wrote:
>>>>
>>>> > We need a URI for that, so that we can say that "every value of a
>>>> given
>>>> property must be a resource". Basically a way to say "anything that can
>>>> appear as a subject in a triple (and therefore can have its own
>>>> properties).
>>>> We have always used rdfs:Resource for that and it worked well in
>>>> practice -
>>>> and rdfs:Literal to say "every datatype". rdfs:NonLiteral does not
>>>> exist.
>>>> OWL had owl:ObjectProperty and owl:DatatypeProperty, and if you left
>>>> their
>>>> range empty then they had that default interpretation. How was this ever
>>>> supposed to work in RDF Schema?
>>>>
>>>> RDFS never needed to address this distinction (arguably because it's
>>>> not s
>>>> schema language). It is certainly better to mint a new term than to
>>>> confuse
>>>> the meaning of an existing term.
>>>>
>>>
>>> I would be OK with a different term but this should then become the
>>> superclass
>>> of all other classes, so that the inheritance model is consistent.
>>> Currently
>>> only rdfs:Resource can play this role I think, but that unfortunately
>>> includes
>>> literals. And owl:Thing would suck in way too much complexity just for
>>> this
>>> technical detail (and existing models that use rdfs:subClassOf
>>> rdfs:Resource
>>> would be excluded too).
>>>
>>> Holger
>>>
>>>
>>
>> It appears that you are asking for the class whose instances are all
>> resources excluding literal values.  The expressive power required for
>> this class goes well beyond the bounds of RDFS.
>>
>> This new class cannot be the superclass of all classes.  It is not a
>> superclass of the class that is the fixed meaning of rdfs:Resource, of
>> course, and it is also not a superclass of class that is the fixed
>> meaning of rdfs:Literal or of any of the datatype classes.  Making this
>> class a superclass of all classes would break RDFS.
>>
>> It would also not be the case that the meaning of all IRIs and blank
>> nodes would belong to this new classes.  In RDF the meaning of an IRI or
>> a blank node can be a literal value.
>>
>>
>> peter
>>
>>
>

Received on Saturday, 20 December 2014 16:24:31 UTC