Re: doubt about "Synset / Concept" class

On Fri, May 10, 2013 at 1:15 PM, Jorge Gracia <jgracia@fi.upm.es> wrote:

> Hi John,
>
> > Firstly, we should bear in mind that SKOS is not an ontology:
>
> Well, ontologies are resources representing the conceptual model
> underlying a certain domain, describing it in a declarative fashion
> cleaningly separated from procedural aspects [1]. In that sense, and
> also in Grubber's traditional definition [2], SKOS models can be
> considered ontologies. Although, of course, they are not "formal"
> ontologies (the spectrum of formality is wide, as in Lassila's
> classification [3]).
>
True... Lassila, in fact, accepts that a list of words is an ontology as
well. He also distinguishes clearly between formal and informal ontologies.
The proposal would be to make this distinction as well with different
properties to show if we are mapping to an informal model or a formal model
(again because for formal models we also need to express valence structure)

>
> > As such, we have two ways to go as a group. We could be in the very
> > prescriptivist camp of saying "SKOS models are not ontologies, we should
> > explicitly tell people they have to link to SKOS models differently".
> > Alternatively, we could be in the permissive camp "Many people use SKOS
> as
> > ontologies, we should accommodate this... (and SKOS is close enough to
> > ontologies that the difference does not really matter)". This is
> therefore
> > just a question of documentation, and perhaps the best solution is to say
> > nothing at all (the prescriptivists aren't upset and the permissivists
> are
> > not disallowed).
>
> Yes, I agree that is the best option (avoid commitments to any view),
> although we still have to decide which domain/ranges will have our
> ontology-lexicon mapping properties (so some commitments made).
>
The only property for which it matters would the reference/isReferenceOf
and for technical reasons it is better not to state this (think about how
would you do this: owl:Thing ∐ skos:Concept does not work well as
skos:Concept ⊑ owl:Thing, and even stating owl:Thing is poor because even
RDFS reasoners would infer that every reference is an individual)

>
> > Stated equivalence between symbols, e.g., (onto:SamuelClemens owl:sameAs
> onto:MarkTwain)
> > Inferred equivalence between symbols, e.g., (onto:Yeti ≡ ⊥ ∏
> GreatestNaturalNumber ≡ ⊥ ⊨Yeti ≡ GreatestNaturalNumber)
>
> I am not sure if you can entail that two concepts are the same if they
> share the same (empty) set of instances.
>
Well, as the equivalent class property is transitive and reflexive, it will.

Moreover, this question does not really concern usability, in both cases
the users have to learn a dichotomy:

1/ I use ontolex:means to refer to a skos:Concept if it an intensional
model and ontolex:reference if it is an "ontology"
2/ I use ontolex:means for skos:Concepts and ontolex:reference for OWL
entities

Also, in both cases linking to SKOS is supported, we just note in one model
the formality of the "ontology" and in the second the intended use of the
"ontology".

Regards,
John

>
> Regards,
> Jorge
>
> ----
>
>
> [1] Philipp Cimiano. Ontology learning and population from text:
> Algorithms, evaluation and applications. Springer, October 2006
> [2] Thomas R. Gruber. Toward principles for the design of ontologies
> used for knowledge sharing. International Journal Human Computer
> Studies, vol. 43, pages 907-928, November 1995.
> [3] Ora Lassila & Deborah L. McGuinness. The Role of Frame-Based
> Representation on the Semantic Web. Technical report, Knowledge
> Systems Laboratory Stanford University, KSL-01-02, 2001
>