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Re: On linking vocabularies (Was: SKOS for schema.org proposal for discussion)

From: Antoine Isaac <aisaac@few.vu.nl>
Date: Mon, 14 Oct 2013 20:44:36 +0200
Message-ID: <525C3B94.2050207@few.vu.nl>
To: Guha <guha@google.com>
CC: "<public-vocabs@w3.org>" <public-vocabs@w3.org>
Hi,

Sure, I think I agree. I might have expressed myself quite wrongly in fact. I meant to say that I was happy with the under-specification of schema:sameAs, and that this under-specification could actually allow to capture some of the semantics of skos:exactMatch, which is not itself a monster of formal axiomatization.

Antoine


> We can define terms as precisely as we would like, but in the end, the meaning is in the usage. And in practice, webmasters cannot be expected to dive into nuances as much as this group does (or would like them to).
>
> And in a super distributed system like the web, we can be very very sure that almost every integrity constraint will be violated!
>
> guha
>
>
> On Mon, Oct 14, 2013 at 2:25 AM, Antoine Isaac <aisaac@few.vu.nl <mailto:aisaac@few.vu.nl>> wrote:
>
>     Hi Jeff,
>
>     I think Niklas' original email was about to assert equivalences between classes or properties between SKOS and schema.org <http://schema.org>, not equivalences at the level of instances (of skos: or schema:Concept).
>
>     Now, there's some value discussing how to represent what in SKOS is represented as skos:exactMatch (at the level of Concept instances). As you hint, this one was introduced because the strict semantics of owl:sameAs didn't fit the kind of softer equivalence cases we wanted to capture. And be compatible with a couple of constraints.
>
>     But in fact schema:sameAs [1] is quite different from owl:sameAs, and it could be good. In fact at the time Jean can with the proposal I was involved with, [1] was not existing. It may be worth dropping a line in the new wiki page for the proposal, saying whether we regard schema:sameAs a good property to use for skos:exactMatch.
>
>     (this in practice would amount to declare
>     skos:exactMatch rdfs:subProperty schema:sameAs
>     which brings us back to the original linking level that Niklas wanted ;-) )
>
>     Cheers,
>
>     Antoine
>
>     [1] http://www.w3.org/wiki/__WebSchemas/sameAs <http://www.w3.org/wiki/WebSchemas/sameAs>
>
>         Hopefully, Schema.org<http://Schema.org> won't carry-forward some of the SKOS constraints in its "equivalent" terminology (whatever that ends up being). For example, it is a SKOS S14 constraint violation to say that the LCSH concept of World War 2 (http://id.loc.gov/__authorities/subjects/__sh85148273 <http://id.loc.gov/authorities/subjects/sh85148273>) is "the same as" the DBpedia concept (http://dbpedia.org/resource/__World_War_II <http://dbpedia.org/resource/World_War_II>).
>
>
>         On those rare occasions where the distinction matters, SKOS should be used. Most cases, though, shouldn't need this fussiness.
>
>         Jeff
>
>
>
Received on Monday, 14 October 2013 18:45:05 UTC

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