W3C home > Mailing lists > Public > public-vocabs@w3.org > May 2013

Re: Official OWL version outdated

From: Holger Knublauch <holger@topquadrant.com>
Date: Fri, 17 May 2013 10:00:23 +1000
Message-ID: <51957317.1030903@topquadrant.com>
To: public-vocabs@w3.org
Ok, I have updated the ontology as discussed - a few properties now have 
mixed ranges allowing both strings or object values, using owl:unionOf.

The "single-range" version is still available as an alternative for 
those who prefer that.



On 5/17/2013 5:31, Bo Ferri wrote:
> Hi Holger,
> On 5/16/2013 12:10 AM, Holger Knublauch wrote:
>> Hi Bo,
>> thanks for your feedback.
>> On 5/16/2013 4:56, Bo Ferri wrote:
>>> Hi Holger,
>>> thanks a lot for providing this well-thoughtout schema.org to proper
>>> RDF(S) mapping. Good work! I really endorse the mappings for the
>>> schema/ontological terms that make use of the well known terms from
>>> OWL and RDFS (instead of schema:Class etc.).
>>> However, I'm wondering why you've introduced a new name space
>>> 'schemax' to create new classes, whose ranges could also be modelled
>>> via owl:unionOf, or?
>> Yes I agree this isn't perfect and that's also the main reason why I
>> marked the current version as "experimental". I would like to get more
>> feedback on this.
>> The main reason for just having a single range with named union classes
>> is that many tools (including some of our own) wouldn't know what type
>> of widget to display and how to best allow users to select values.
> Yes, okay. You made the point. So one has to decide between defacto 
> best practice ontology design and "real world" practical 
> applicability. I'm not sure, however, I think since popular ontologies 
> such as GoodRelations are also doing it this way, there must be a 
> practical solution to implement it with a satisfiable UX, or? Albeit, 
> I guess you are looking for a rather generic approach here ... where 
> it might get a bit more complicated ;)
>> This
>> problem is especially obvious for mixed properties that allow xsd:string
>> or objects.
>> I will rename the current version (with the single range) and change the
>> converter to use owl:unionOf ranges, then replace the version to use
>> that convention. Then people have the choice which range convention they
>> use.
> coolo!
>> Question: Some properties either allow objects or xsd:string values.
>> Shall I leave those in tact or shall I suppress the xsd:string choice?
>> If I leave them in I would need to turn them into rdf:Properties. I have
>> not seen properties that have such a mixed union anywhere, but I guess
>> it would be more correct to preserve them. Another idea would be to
>> introduce different properties for the string part, e.g.
>> schema:xy-string, but this would introduce different URIs. Please let me
>> know your thoughts.
> I would endorse the rather generic, not OWL-DL compatible way by 
> utilising rdf:Property for relationships that could be datatype or 
> object properties. However, I know that this a decision against OWL-DL 
> (see also this discussion [1]). Two properties, which bare the same 
> meaning, "only" for OWL-DL compatibility will confuse the common user 
> of the vocabulary. I know that one could also implement OWL property 
> chain axioms or similar mechanism, but I guess that this would be a 
> bit against the nature of schema.org (which is nowadays already to big 
> to grasp for the common web developer (re. number of types etc.) - but 
> this is another topic ... ;) ).
> Cheers,
> Bo
> [1] 
> http://answers.semanticweb.com/questions/1367/restrictions-on-rdfproperty
Received on Friday, 17 May 2013 00:01:13 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:29:27 UTC