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Re: Proposal for new type : Vocabulary

From: Bernard Vatant <bernard.vatant@mondeca.com>
Date: Mon, 9 Dec 2013 12:45:19 +0100
Message-ID: <CAK4ZFVHYuw=UM=-eVSSUp32DMefxWwW5-B8sG0gt+emKbCbywQ@mail.gmail.com>
To: Antoine Isaac <aisaac@few.vu.nl>
Cc: Charles McCathie Nevile <chaals@yandex-team.ru>, "<public-vocabs@w3.org>" <public-vocabs@w3.org>
Hello Antoine and Chaals

2013/12/7 Antoine Isaac <aisaac@few.vu.nl>

> Hi Chaals, all (I guess there was a problem in my email's receipients)
> I think I'm in favour of having owl:Ontology, and if there's a need to get
> an umbrella for glossaries/thesauri/other classifications, to re-use
> skos:ConceptScheme or something like that.

As you write yourself, owl:Ontology and skos:ConceptScheme are different
animals, both specified in such a way that they lead to a variety of
different interpretations, as we have learnt in the LOV project, but in any
case specified for specific types of vocabularies.

> Diane says there are use cases, but http://metadataregistry.org/ still
> makes a big difference between "Vocabularies"  (there, akin to SKOS
> ConceptSchemes) and "Element Sets" (there, akin to OWL Ontologies).

Yes indeed. But having a general type in schema.org allows specific
resources to have their specific subtypes, named in their local parlance.
If I understand well Chaals' point, I agree. From a search engine viewpoint
(which is all schema.org is about), users will certainly look for terms
without specifying if they are looking for a skos:Concept, a rdfs:Class, a
wordnet:Synset etc or just a word in a flat glossary not specified in any
RDF dialect. I would see owl:Ontology etc fit in additionalType

> In fact Bernard has not answered my question on starting to have
> everything in LOV.

This is a rather different issue. We have restricted so far the scope of
LOV to RDFS and OWL ontologies in order to stay focus, cope with limited
resources etc. For example the VOAF constructions and queries computing
links between vocabularies are taking into account so far RDFS and OWL
constructions, not SKOS mapping relationships for instance.The next version
of LOV on which we are working will certainly be more open in scope, but in
any case the schema.org/Vocabulary proposal goes beyond such
considerations. It could be used for non-RDF vocabularies, which will stay
in any case outside the scope of LOV.

To be more precise: I do not see the the use case for having *only* the
> generalization of Ontology and ConceptScheme. I see the point in making
> inventories of both types of resources; but because the two categories are
> usually made to meet quite different requirements, I'm skeptical about the
> value of blurring the line.

The line is already blurred anyway, as examples I mentioned are showing.
LoC relators are both skos:Concept and rdf:Property. Th Geonames ontology
includes the feature codes as SKOS concepts etc.

> About rdfs:isDefinedBy vs an hypothetical "uses" property (between
> Vocabulary and individual classes/properties or concepts). I agree with
> Chaals: the differences may not survive in this case. More precisely: I
> think it is the "usage" link between vocs and their elements that will get
> more traction. The "defined" link is more a provenance/process aspect; it's
> important for specific scenarios, which may not be really sought by the
> general schema.org users. Therefore it would seem dangerous to me to use
> rdfs:isDefinedBy, because its original meaning would be 'highjacked' by the
> more prominent requirement.

 Indeed. So you agree with a generic "isDefinedBy". Or  reuse
http://schema.org/isPartOf which has a very restricted use so far. Unless
Vocabulary can fit under http://schema.org/CollectionPage. A Vocabulary is
after all somehow a collection of terms as an ImageGallery is a collection
of images, but this seems a bit far-fetched ...

> Antoine
> On 12/6/13 9:46 PM, Charles McCathie Nevile wrote:
>> On Fri, 06 Dec 2013 11:19:06 +0100, Antoine Isaac <aisaac@few.vu.nl>
>> wrote:
>>  Hi Bernard,
>>> +1 for including Vocabulary. It would fill in the gap of not having
>>> included an equivalent to skos:ConceptScheme in the MiniSKOS proposal.
>>> I'm however a bit skeptical about having just one class for ontologies
>>> (sets of classes and properties a la schema.org) and other SKOS-level
>>> vocabularies (classifications, thesauri) in one big bag. I'll be the first
>>> one to agree with you that the two types of vocabularies are not exclusive.
>>> But the functions are quite different.
>> I'm not so sure - and I certainly don't know of a practical way to
>> describe the difference to non-professionals.
>>  In fact trying a litmus test: if the "Vocabulary" class was to include
>>> SKOS Concept schemes, would the Linked Open vocabularies start gathering
>>> SKOS concept schemes as well?
>> That would seem like a reasonable thing to me. Although they might be
>> selective about them for other reasons.
>>  An extra would be to have a "definedBy" property to link instances of
>>>> the oncoming Topic class to an instance of Vocabulary.
>>>>  Is this skos:inScheme in the SKOS world, or really rdfs:isDefinedBy?
>>> The nuance (creating vs. including/re-using) can be in fact really
>>> important. (and I personally feel that both aspects are worth representing).
>> The problem is that in practice, where a term is originally defined stops
>> being relevant once people start including it in other places with
>> differences, and getting traction.
>> I have nothing in principle against preserving the differences, but I am
>> sceptical that they will survive contact with reality, and not sure they
>> are worth struggling for.
>> cheers
>> Chaals


*Bernard Vatant*
Vocabularies & Data Engineering
Tel :  + 33 (0)9 71 48 84 59
Skype : bernard.vatant
3 cité Nollez 75018 Paris, France
Follow us on Twitter : @mondecanews <http://twitter.com/#%21/mondecanews>
Received on Monday, 9 December 2013 11:46:11 UTC

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