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Re: URIs for public data - was RE: URIs for Concept & ConceptScheme - best practice?

From: Mike Collett <mike@vocman.com>
Date: Mon, 17 May 2010 15:22:49 +0100
To: "public-esw-thes@w3.org" <public-esw-thes@w3.org>
Message-ID: <C8170FC9.2B894%mike@vocman.com>
Kevin and others

I also think it is a very sensible approach to distinguish between
resolution and identification and solutions such as described in your blog
seem a sensible approach.

More generally,:
As a policy or ideal it does not seem to make sense to promote the ³http
URIs .. 'path-like' structure .. interpreted as a tree.² as suggested by
Simon. It may work in some specific well-defined, closed circumstances but
should not become a rule or even a recommendation.

And to Simon¹s question ³is it smart to have the URI for a SKOS concept to
be just an extension of the URI for the SKOS concept scheme?² - the short
answer is no.

Simon points out some of the problems of these approaches himself.

Ontologies (taxonomies and the rest) can be very fluid structures especially
during early stages of their evolution. Having a tree structure in a uri to
identifies a concept assumes that its place in the structure is known BEFORE
its needs to be identified. This is not always the case. Even whether or not
an object is a data.gov.uk Œschool¹ is not as straightforward as it might
seem. 

Not all concepts fit neatly into a single category or structure.

Not all structures will be static and categories change in time and across
contexts, regions, nations and sectors.

If there is some information in the uri tree structure to be assumed by a
person reading it this encourages dependency on this single, static
structure rather than checking if the implied relationships are still
considered correct. Having a casual user being able to ³navigate between
parent and child by URI twiddling² strikes me as dangerous if they are to
give any weight to, or make important decisions on their twiddling.

There will also be a tendency to be lazy and use the words in the parts of
the uri to infer preferred labels and their associated implied semantics.
This carries with it likely misinterpretation, for example as language
changes, as well as having a distinct monolingual, monocultural bias.

Cheers
Mike 7:-D
-----------
Mike Collett
Vocabulary Management Group
+44 7798 728 747
------------
www.vocman.com
mike@vocman.com




From: Kevin Richards <RichardsK@landcareresearch.co.nz>
Date: Sat, 15 May 2010 09:07:20 +1200
To: Rob Tice <rob.tice@K-INT.COM>, "public-esw-thes@w3.org"
<public-esw-thes@w3.org>, "simon.cox@jrc.ec.europa.eu"
<simon.cox@jrc.ec.europa.eu>
Subject: Re: URIs for public data - was RE: URIs for Concept & ConceptScheme
- best practice?
Resent-From: <public-esw-thes@w3.org>
Resent-Date: Fri, 14 May 2010 21:11:17 +0000

I agree that it is important to distinguish between resolvability of the
identifier and the 'identification' function of it.  I have recently blogged
about a similar topic (somewhat of a blog novice however) - see
http://biodiv-dev.blogspot.com/
>
Kevin Richards

Sent from my HTC

----- Reply message -----
From: "Simon Cox" <simon.cox@jrc.ec.europa.eu>
Date: Sat, May 15, 2010 1:56 AM
Subject: URIs for public data - was RE: URIs for Concept & ConceptScheme -
best practice?
To: "&apos;Rob Tice&apos;" <rob.tice@k-int.com>, "public-esw-thes@w3.org"
<public-esw-thes@w3.org>

 <http://biodiv-dev.blogspot.com/ <br>
Rob - 
 
I'm somewhat familar with the data.gov.uk policy in this area, in particular
the plans from the UK Location Program (I've been providing feedback to the
latter, on behalf of JRC who lead the INSPIRE initiative, and the OGC where
I chair the 'Naming Authority').
 
As I understand it data.gov.uk is aware of the issue, and is planning to
address the problem by using domains that represent concepts (schools,
roads, etc) rather than the todays name for the govt. department that
administers the resource (dcsf yesterday, education today).
This makes sense to me - the name has to be robust in the face of typical
organizational instability.
 
But that's about the beginning of the URI: I'm focussing on the other end
;-)
 
Simon
--------------------------------------------------------
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/ <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.

 

> 
> From: Rob Tice [mailto:rob.tice@k-int.com]
> Sent: Friday, 14 May 2010 15:44
> To: 'Simon Cox'; public-esw-thes@w3.org
> Subject: RE: URIs for Concept & ConceptScheme - best practice?
> 
> Simon
>  
> Anyone who is in the UK at the mo and is in the business of managing
> identifiers for resources within government departments might possibly be
> ruminating on why uri¹s don¹t actually always make good identifiers.
>  
> For info.
>  
> http://www.education.gov.uk
>  
> versus
>  
> http://www.dcsf.gov.uk
>  
>  
> Proper separation between identification and resolution  anyone (Ducks behind
> the parapet J)
>  
>  
> Cheers
>  
> Rob
>  
>  
>  
> 
> From: public-esw-thes-request@w3.org [mailto:public-esw-thes-request@w3.org]
> On Behalf Of Simon Cox
> Sent: 14 May 2010 13:42
> To: public-esw-thes@w3.org
> Subject: URIs for Concept & ConceptScheme - best practice?
>  
> I'm thinking about identifier policies for ontologies and concept-schemes..
> 
>  
> 
> In work that I have done previously on identifier policies for Open Geospatial
> Consortium and for Commission for Geoscience Information we used the
> identifier scheme largely as a way to enforce certain governance arrangements
> for resource publication. The general principle is that a URI 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 must come from a specific
> register; and different parties are authorized to modify different registers.
> So we end up with a delegation system. This kind 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 between
> resources, in particular 'ownership' of children by their parents.
> Notwithstanding the REST principle that information is in the representation
> and not the identifier, Cool URIs can be interpreted by users, and typically
> 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 to be
> just an extension of the URI for the SKOS concept scheme?
> 
>  
> 
> e.g. 
> 
> <http://resource.geosciml.org/concept/unit-rank/bed> skos:inScheme
> <http://resource.geosciml.org/concept/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 no
> limit on the number of inScheme properties a Concept can have?)
> 
> (2) there must be some others
> 
>  
> 
> 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/ <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.
> 
>  


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Received on Monday, 17 May 2010 22:38:47 GMT

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