Re: narrowerThan leftOperands

Hi Renato,

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> 
>> -          In other words: what makes odrl:narrowerThan different from skos:broader(Transitive)?
> 
> I think the key difference is (and @Ivan and others  can chime in if I am wrong) is that skos:narrower is only used to assert a direct (i.e., immediate) hierarchical link between two SKOS concepts.
> 
> But in our case, we are asserting more than this. For example, when we say:
>   odrl:stream odrl:narrowerThan odrl:use
> 
> Even though - conceptually - odrl:use is a direct hierarchical link to odrl:stream, skos:narrower does not capture the implications of this link.
> That is, these terms are operational actions, and their linkage may mean that one invalidates the other (eg conflict detection).
> (ie you are allowed to stream but prohibited to use)
> 
> Hence, odrl:narrowerThan asserts stronger semantic implications than skos:narrower (ie actions terms are more than just a hierarchy of concepts).

That is absolutely correct. The SKOS relations do not carry any further semantics beyond stating them, and we need more than those. Because we want to attach an additional, and very specific semantics to the relationship, we need a distinct on.

Let me be, actually, very heretic here (I was not part of the original ODRL discussions, remember?): I wonder what the embedding of ODRL into SKOS term bring us in the first place. SKOS is perfect for, say, library related vocabularies (this was one of the primary inspirations for SKOS after all), but for a more, say, "operational" vocabulary like ODRL I fail to see the advantage of having them. On the other hand, it seems to complicate the ontology.

I am not against keeping SKOS if the majority of the group wants to keep it (for, e.g., historical reasons), but I think it is a valid question…

Ivan

P.S. I hope Antoine will still accept to talk to me after this remark:-)

----
Ivan Herman, W3C
Publishing@W3C Technical Lead
Home: http://www.w3.org/People/Ivan/ <http://www.w3.org/People/Ivan/>
mobile: +31-641044153
ORCID ID: http://orcid.org/0000-0003-0782-2704 <http://orcid.org/0000-0003-0782-2704>