Re: Modeling change in and between schemes using SKOS - the problem of persistent URIs

Hi Andrew:

On 29-Aug-06, at 6:06 AM, Houghton,Andrew wrote:

>
>> From: public-esw-thes-request@w3.org
>> [mailto:public-esw-thes-request@w3.org] On Behalf Of Aida Slavic
>> Sent: 29 August, 2006 08:14
>> To: Jakob Voss; public-esw-thes@w3.org
>> Subject: RE: Modeling change in and between schemes using
>> SKOS - the problem of persistent URIs
>>
>> In UDC cancellations,
>> additions and changes of the scheme are also distributed to
>> users as separate files every year (e.g. cancellation file
>> (text export, short version) is at
>> http://www.udcc.org/cancellations.htm.
>> Am I wrong in assuming that in a scenario related to SKOS (or
>> terminological
>> services)
>> these data would be kept all together?
>
> Because SKOS is based on RDF, it would be wrong to assume that
> the change data needs to be kept with the actual concept
> information, e.g., scope notes.  You could have:
>
> <skos:Concept rdf:about="uri">
>   <!-- definition of the concept -->
> </skos:Concept>
>
> <skos:Concept rdf:about="uri">
>   <!-- changes related to the concept -->
> </skos:Concept>
>
> both skos:Concept could be in the same resource or different
> resources and RDF will piece the information together.

Exactly.  We're interested and worried about the creation of new URIs  
where there need be only one.  How would one piece together that  
information?

>
>> P.S. I read somewhere (ages ago) about Dewey's consideration
>> to tie the concept ID with a scheme edition and notation
>> through a structured URI (name of the scheme/edition/notation).
>> This essentially means a different URI for the same concept
>> (with or without some changes in text or scope). I don't know
>> how this approach would help an automatic update of the
>> scheme in the users authority files or track
>> changed/cancelled classes. I am not sure the proposed
>> suggestion is still valid though.
>
> I probably wrote that and it is still a concern with SKOS/RDF in
> regard to Dewey and possible other vocabularies.  There are
> multiple issues around identifiers for Dewey which essentially
> has put our SKOS work on hold.
>
> One of the issues that Dewey faces has to do with concepts being
> deprecated in one edition and reused in another edition for a
> different concept.  Another issue has to do with options allowed
> by the classification.
>
> For the deprecated concept issue, if we have a URI like,
>
> <http://dewey.oclc.org/123.45>

This in my mind is a label, not a concept.  Am I wrong to consider  
this a label?

>
> that points to the concept peaches in Edition 19 and that concept
> is deprecated in Edition 20, but then reused in Edition 21 for
> apples, then we perceive a serious problem, based upon our limited
> knowledge of RDF.  RDF would take both those skos:Concept elements
> and merge them together.  Thus, mixing up the information for the
> concepts in Edition 19 and 21.

Right!  So we need to separate out labels from concepts.  SKOS does  
this yes?

>
> To solve this issue we proposed using a URI that included scheme,
> edition, translation, and notation.  It would keep the skos:Concept
> elements from being merged by RDF.  To track relationships of
> concepts between editions we thought that we could use OWL or use
> the SKOS mapping vocabulary.

This ties scheme to concept which goes against SKOS modeling yes?   
This is still separate from our question of instances of concepts.   
But it's good fodder for consideration on SKOS modeling concepts  
independent of schemes.  Is it something we're going to want to do?   
Or are we always going to want to link concepts with schemes?

>
> For the options allowed issue, it's a similar problem but instead
> of deprecated concepts we are dealing with relocated concepts.  An
> example of this appears in the religion schedule.  Many would say
> that Dewey's religion schedule is biased toward Christianity.  An
> option exists where you can relocate the numbers in the religion
> schedule.  This option is used in the Arabic edition where Islam
> is the predominate religion and not Christianity.  So the concept
> identifier 234.56 in the English edition of Dewey could mean
> something totally different in the Arabic edition.
>
> How these issues can be properly managed with SKOS, RDF, OWL and
> URI we are still trying to figure out.  We are not RDF or OWL
> experts which complicates matters.  If anyone on the list has any
> ideas on URI's for Dewey in SKOS, pros or cons about what I
> discussed above, please feel free to contact me off-list.  We are
> very interested in hearing a diversity of opinions, to help us
> formulate a direction.
>
>
> Andy.
>
> Andrew Houghton, OCLC Online Computer Library Center, Inc.
> http://www.oclc.org/about/
> http://www.oclc.org/research/staff/houghton.htm
>
>

Thanks for thinking about this,
joe



Joseph T. Tennis, PhD
Assistant Professor
Coordinator for the MAS and MLIS First Nations Concentration
School of Library, Archival and Information Studies
The University of British Columbia
301 - 6190 Agronomy Road
Vancouver, BC V6T 1Z3
CANADA
phone: 1.604.822.2431
fax: 1.604.822.6006
jtennis@interchange.ubc.ca
http://www.slais.ubc.ca/PEOPLE/faculty/tennis-p/index.htm

Received on Friday, 1 September 2006 16:31:42 UTC