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RE: URIs for Concept & ConceptScheme - best practice?

From: Simon Cox <simon.cox@jrc.ec.europa.eu>
Date: Wed, 26 May 2010 09:05:04 +0200
To: <public-esw-thes@w3.org>
Message-ID: <7D5521051DE64AF9A6E974D14AA211B4@H07.jrc.it>
So the guidance is mixed overall. 
CoolURIs suggests leveraging the path, but ontology variability suggests not
taking it too seriously. 

Musing a little more: of course hash URIs always imply an ownership

Simon Cox

-----Original Message-----
From: public-esw-thes-request@w3.org [mailto:public-esw-thes-request@w3.org]
On Behalf Of Rob Tice
Sent: Tuesday, 18 May 2010 15:07
To: 'Antoine Isaac'; public-esw-thes@w3.org
Subject: RE: URIs for Concept & ConceptScheme - best practice?

I would endorse Antoine's comment. 

'And of course any cool URI tricks should not replace proper representation
of knowledge about the resources!'

In addition (to follow up on Mike's point): 

The process of developing ontologies/schemes etc and releasing to the world
(or maybe assigning URI's) when finished is only one possible approach.  

When the actual development/evolution of the concepts, schemes and
hierarchies also has to be shared and public (even if this is only public
within an organisation), assigning URI's based on structure just doesn't
work well.



-----Original Message-----
From: public-esw-thes-request@w3.org [mailto:public-esw-thes-request@w3.org]
On Behalf Of Antoine Isaac
Sent: 18 May 2010 11:29
To: public-esw-thes@w3.org
Subject: Re: URIs for Concept & ConceptScheme - best practice?

Hi everyone,

> On Fri, May 14, 2010 at 02:41:39PM +0200, Simon Cox wrote:
>> I'm thinking about identifier policies for ontologies and
>> In work that I have done previously on identifier policies for Open 
>> Geospatial Consortium and for Commission for Geoscience Information 
>> we
>> the identifier scheme largely as a way to enforce certain governance 
>> arrangements for resource publication. The general principle is that 
>> a
>> is composed of a number of fields. A new URI can only be minted if 
>> the values in all the fields are valid; the allowable value for each 
>> field
>> come from a specific register; and different parties are authorized 
>> to modify different registers. So we end up with a delegation system. 
>> This
>> of scheme uses the URI structure for internal governance purposes, 
>> within the community.
>> But http URIs have a 'path-like' structure which can be interpreted 
>> as a tree. Read in this way, the URI scheme impies certain 
>> relationships
>> resources, in particular 'ownership' of children by their parents.
>> Notwithstanding the REST principle that information is in the
>> and not the identifier, Cool URIs can be interpreted by users, and
>> support navigation through tweaking the URI (many refs).  This kind 
>> of scheme is aimed at external users.
>> Following this approach: is it smart to have the URI for a SKOS 
>> concept
>> be just an extension of the URI for the SKOS concept scheme?
>> e.g.
>> <http://resource.geosciml.org/concept/
>> <http://resource.geosciml.org/concept/unit-rank/bed>  unit-rank/bed> 
>> skos:inScheme<http://resource.geosciml.org/concept/
>> <http://resource.geosciml.org/concept/unit-rank>  unit-rank>.
>> I'm assuming slash URIs, since I want the server to do most of the 
>> work, supporting content-negotiation, etc.
>> The advantage in this approach is that a casual user can navigate 
>> between parent and child by URI twiddling.
>> But possible gotchas are
>> (1) it assumes exactly one parent
>>     - it requires every concept to be in a scheme
>>     - it privileges one scheme above any others (though I think there 
>> is
>> limit on the number of inScheme properties a Concept can have?)
>> (2) there must be some others
> I don't see any problem with this, as long as the scheme is the 
> definitive (i.e., authoritative) scheme for that concept.
> Slightly tangential, but you might also be interested in:
> http://www.cabinetoffice.gov.uk/media/308995/public_sector_uri.pdf
> http://www.ivoa.net/Documents/latest/Vocabularies.html

Very good guidelines, indeed!

About Simon's questions.
+1 for Alistair and Johan's comments on using some concept scheme 
+"label" in
the path for for the concepts that they originally coined.
And I would advise against using the parent concepts in the path, unless
your scheme has a strict tree structure. Otherwise you'll have to make some
hard choices at some places...

And of course any cool URI tricks should not replace proper representation
of knowledge about the resources! As Rob has pointed out, the data for some
resources may change, making obsolete even the best patterns of the



>> I'd be interested in comments.
>> --------------------------------------------------------
>> Simon Cox
>> European Commission, Joint Research Centre Institute for Environment 
>> and Sustainability Spatial Data Infrastructures Unit, TP 262 Via E. 
>> Fermi, 2749, I-21027 Ispra (VA), Italy
>> Tel: +39 0332 78 3652
>> Fax: +39 0332 78 6325
>>   <mailto:simon.cox@jrc.ec.europa.eu>  mailto:simon.cox@jrc.ec.europa.eu
>>   <http://ies.jrc.ec.europa.eu/simon-cox>
>> http://ies.jrc.ec.europa.eu/simon-cox
>> SDI Unit:<http://sdi.jrc.ec.europa.eu/>  http://sdi.jrc.ec.europa.eu/ 
>> IES Institute:<http://ies.jrc.ec.europa.eu/>
>> JRC:<http://www.jrc.ec.europa.eu/>  http://www.jrc.ec.europa.eu/
>> --------------------------------------------------------
>> Any opinions expressed are personal unless otherwise indicated.
Received on Wednesday, 26 May 2010 07:16:59 UTC

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