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

I was using that facetiously (which doesn't come across well in email, I 
know.)

But, rather than picking at nits, can we agree that we have a 
requirement, or no? And if no, what would be the reason?

kc

On 12/20/14 8:24 AM, Peter F. Patel-Schneider wrote:
> 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
>>>
>>>
>>
>

-- 
Karen Coyle
kcoyle@kcoyle.net http://kcoyle.net
m: 1-510-435-8234
skype: kcoylenet/+1-510-984-3600

Received on Saturday, 20 December 2014 17:11:28 UTC