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Re: INSEE releases OWL ontology and RDF data for geographical entities

From: <creed@opengeospatial.org>
Date: Fri, 4 Aug 2006 11:04:58 -0400 (EDT)
Message-ID: <63295.129.19.2.4.1154703898.squirrel@mail.opengeospatial.org>
To: "Dan Connolly" <connolly@w3.org>
Cc: "Eric van der Vlist" <vdv@dyomedea.com>, "Bernard Vatant" <bernard.vatant@mondeca.com>, semantic-web@w3.org, public-xg-geo@w3.org, "Franck Cotton" <franck.cotton@insee.fr>

I may be out in left field, but I was wondering (RDF aside), what is the
relationship of this activity with other similar geo-tagging activities,
such as http://geotags.com/geo/draft-daviel-html-geo-tag-00.html? Reason I
ask is that from a standards persepctive, it would be nice to have one
common approach (information model) for expressing a URL/URI and then have
various serializations (XML or straight http or RDF etc) based on
implementation requirements.

Thanks for the clarification.

Regards

Carl
OGC


>
> On Fri, 2006-08-04 at 09:28 +0200, Eric van der Vlist wrote:
>> Hi,
>
> Hi Eric,
>
>> Le jeudi 03 août 2006 à 23:26 +0200, Bernard Vatant a écrit :
>> >
>> > Dan
>> > > did you consider using # rather than /? i.e.
>> > >   http://rdf.insee.fr/geo#code_commune
>> > > rather than
>> > >   http://rdf.insee.fr/geo/code_commune
>> > > especially for ontologies, it's a lot easier to manage.
>> > >
>> > We did consider. Actually my first version of the ontology used a #
>> > namespace. Eric (in cc)  was the one who suggested a / namespace,
>> > especially for the data and somehow convinced the rest of us. That was
>> > six months ago, but if I remember correctly, the idea was that at some
>> > point, each instance URI would  be (should be, hopefully will be)
>> > associated  with, and access to, a  separate resource, which is not
>> > the case now.
>>
>> Yes, that was the first comment I did on your first proposal end of
>> January.
>>
>> The idea was that to identify a city, http://rdf.insee.fr/geo/COM_80078
>> is better than http://rdf.insee.fr/geo#COM_80078.
>
> You might also consider http://rdf.insee.fr/geo/COM_80078#city for
> the city itself and http://rdf.insee.fr/geo/COM_80078 for a document
> about the city.
>
> If the cities come in natural chunks, perhaps
> http://rdf.insee.fr/geo/COM_800#city78
> for the city and http://rdf.insee.fr/geo/COM_800 for a document about
> the cities in some region.
>
>>  Of course, these URIs
>> are only identifiers but who konws, we might want some day to publish
>> some kind of documentation (like we do in RDDL to document namespaces)
>> at these URIs.
>
> "only identifiers"? sigh. I got the impression you wanted to publish
> information about them in the Semantic Web.
>
>> If we do so, the first URI makes each city a standalone entity while the
>> second one means that they need to be fragments in a huge document which
>> can cause a lot of issues (we don't know which media types we might want
>> to publish and the definition of fragments is inconsistent between media
>> types
>
> It's within your control to choose media types where the definition
> of fragments is consistent. The easiest way is to just use one
> media type: application/rdf+xml .
>
>
>>  (some of them don't even support fragments), the document might
>> grow very large, ...).
>>
>> Now, the thing that we've not considered is to have a namespace URI
>> different from the RDF base.
>>
>> > Agreed, we could have kept the # namespace for the ontology at least.
>>
>> Dan, can you elaborate why that makes ontologies a lot easier to manage?
>
> Because with a # namespace, publishing the ontology just involves
> sticking one static file on a web server. (the URI looks nicer
> if the web server can handle leaving the .rdf or .owl off, but
> that's not completely essential).
>
> And then to look up http://rdf.insee.fr/geo#code_commune , a consumer
> just GETs http://rdf.insee.fr/geo as usual; then when they want
> to look up another term such as http://rdf.insee.fr/geo#subdivision,
> they can save a round trip because they already have it.
>
> Using a / namespace has a higher cost for the producer (redirects)
> and for the consumer (one GET per term rather than one GET
> for the ontology).
>
>
>> Thanks;
>>
>> Eric
>>
>> >
> --
> Dan Connolly, W3C http://www.w3.org/People/Connolly/
> D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
>
>
>
>
Received on Friday, 4 August 2006 15:11:05 GMT

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