Re: FAQ:

missed a "not"

On Fri, May 22, 2009 at 3:09 AM, Alan Ruttenberg
<alanruttenberg@gmail.com>wrote:

> Please consider coordinating with the OWL WG if you plan to pose and answer
> this question in a FAQ. I don't think the below answer is particularly
> accurate or helpful. For one thing, RDF and OWL have model theoretic
> semantics, but this does

^^not^^

> imply the semantics are extensional. For example, we can have have c1
> equivalentClass c2 but c1 differentIndividual c2. I have further criticisms,
> but would rather discuss them in the context of putting together an answer
> that does justice to the two efforts and their aims.
>
> Also, there are some actual differences in the semantics that should be
> mentioned, as SKOS has some semantic conditions that can not be expressed in
> OWL or RDF, such as S14: A resource has no more than one value of
> skos:prefLabel per language tag, which can't be expressed in OWL 1 or OWL
> 2,  or S12: The rdfs:range of each of skos:prefLabel, skos:altLabel and
> skos:hiddenLabel is the class of RDF plain literals, which can't be
> expressed in OWL 1, but probably will be able to be expressed in OWL 2.
> -Alan
> http://sciencecommons.org/about/whoweare/ruttenberg/
>
>
>
> On Wed, May 20, 2009 at 4:47 PM, John F. Madden <john.madden@me.com>
> wrote:
> > Two possible reasons, by my lights:
> > (1) If the goal is mapping legacy terminologies into an RDF dialect:
> > RDF/OWL has a formal, model theoretic, extensional semantics. Most legacy
> > terminologies have an informal semantics that is entirely intensional.
> > Putting them directly into RDF/OWL imputes to them an ability to support
> a
> > kind of inferencing that they were never intended to support. The result
> is
> > liable to be unexpected or undesirable inferences; or in other cases,
> > failure to entail inferences that one would imagine to be natural
> > consequences.
> > SKOS, on the other hand, doesn't treat the legacy terms as classes with
> > extensions (as RDF/OWL does). Yet SKOS still gives one a vocabulary to
> talk
> > about the most important intensional meanings that such terminologies
> tend
> > to use (notions like narrower, broader, related, etc.).
> > (All this is much better said than I ever could in the SKOS Primer.)
> >
> >
> >
> > (2) If the goal is to model a set of terms de novo:
> > For the same reasons as stated in (1), SKOS provides a way to depict
> > informal, notional relations among ideas without having to buy into the
> more
> > rigorous RDF/OWL semantic model, which may be too constraining for
> certain
> > kinds of modeling (for example, the more freewheeling kinds exemplified
> by
> > "concept-mapping", "mind-mapping"; or the type of intuitive models that
> one
> > tends to get from domain experts).
> > John
> >
> > On May 20, 2009, at 3:57 PM, Kevin Doyle wrote:
> >
> > Hi,
> > I have a question I would like to put on the SKOS FAQ, because I don't
> know
> > the answer.  Also, this is the first place that I looked for the answer.
> >  Why SKOS and not OWL?  Or maybe to put the question another way, what
> are
> > the advantages of using SKOS over OWL?
> > Kevin S. Doyle
> > Client Solution Manager
> > Teranode Corp.
> > www.teranode.com
> > Tel: +1-617-710-5155
> >
> >
> >
> >
>
>