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Re: questions about notations / sizes / coordination

From: Jakob Voss <jakob.voss@gbv.de>
Date: Mon, 17 Jul 2006 17:30:27 +0200
Message-ID: <44BBAD13.30902@gbv.de>
To: public-esw-thes@w3.org

Hi again,

Since nobody is awake and interested I try to answer the questions
myself. I wrote:


> 1. How to encode Notations

To encode a notation use xml:lang="alt".

The follwing examples states that there is a DDC number "030" for
"General encyclopedic works":

<skos:Concept
rdf:about="http://www.oclc.org/dewey/versions/ddc22print/#ddc030">
  <skos:prefLabel xml:lang="art">030</skos:prefLabel>
  <skos:prefLabel xml:lang="en">General encyclopedic works</skos:prefLabel>
</skos:Concept>

Note that every concept can only have one preferred notation.


> 2. How to get the size of a collection
> 
> When browsing through a KOS you'd like to get the number of items that
> are indexed with a concept (or with a concept and its subconcepts!). For
> example see
> 
> http://dmoz.org/Arts/Costumes/
> 
> In this case the number of items in class Arts:Costumes (33) is shown,
> but there are only 5 items that are directly indexed with Arts:Costumes
> so you need a way to encode two numbers with a concept - any suggestions
> who to do it in a consistent way?

This is a bit tricky because the number of records depends of the
collection. So you cannot use a simple triple but a new Class is needed.
I hereby introduce the Class "RecordNumber" for a number of records
indexed by a Concept.

The follwing examples states that there are 2 works indexed with DDC
number "030" in the cataloge of Common Library Service (GBV) and 13
works indexed with any DDC number 030, and narrower numbers in the
hierarchy:

<skos:Concept rdf:about="http://gso.gbv.de/DB=2.1/">
  <skos:RecordNumber>
    <skos:recordScheme rdf:resource="http://www.oclc.org/worldcat/"/>
    <skos:recordNumber>2</skos:recordNumber>
  </skos:RecordNumber>
  <skos:RecordNumber>
    <skos:recordScheme rdf:resource="http://www.oclc.org/worldcat/"/>
    <skos:recordNumber>13</skos:recordNumber>
    <skos:expandedRelation
rdf:resource="http://www.w3.org/2004/02/skos/core#narrower">
  </skos:RecordNumber>
</skos:RecordNumber>

This includes 3 new relations:
* skos:recordNumber
* skos:recordScheme
* expandedRelation

To only expand a specific distance you can also think of
* skos:expandedDepth

Any suggestions?


By the way to get the records try

http://gso.gbv.de/DB=2.1/SET=1/TTL=1/CMD?ACT=SRCHA&IKT=1016&SRT=YOP&TRM=ddc+030

and

http://gso.gbv.de/DB=2.1/LNG=DU/SRT=YOP/IMPLAND=Y/CMD?ACT=SRCHA&IKT=8562&TRM=030*


> 3. How to encode concept combinations
> 
> This is slightly complex but important. Maybe it can easily can be
> solved with SKOS Mapping which I have not looked at enough. In some
> thesauri you have non-prefered-terms and relations that point you to use
> a concept in combination with another concept or vice versa to indicate
> postcoordination or precoordination in indexing.

I think that relatedHasPart and relatedPartOf in
http://www.w3.org/2004/02/skos/extensions is not what I meant.

> For instance the concept "Spanish town" could be defined as non-prefered
> and point you to use the two concepts "Spain" and "town"
> (post-coordination) or if you want to have "Spanish town" as a concept
> for indexing (pre-coordination) then "Spain" and "town" both have a
> special kind of associative relationship to "Spanish town".
> 
> How should I encode this in SKOS?

Maybe you would answer to use SKOS mapping:

<skos:Concept>
  <skos:prefLabel xml:lang="es">ciudad</skos:prefLabel>
  <map:exactMatch>
    <map:AND>
      <map:memberList rdf:parseType="Collection">
        <skosl:Concept>
          <skos:prefLabel>Spain</skos:prefLabel>
        </skos:Concept>
        <skosl:Concept>
          <skos:prefLabel>Town</skos:prefLabel>
        </skos:Concept>
      </map:memberList>
    </map:AND>
  </map:exactMatch>
</skos:Concept>

But this is too complex. How about:

<skos:Concept rdf:about="#ciudad">
  <skos:prefLabel xml:lang="es">ciudad</skos:prefLabel>
  <skos:useCombination rdf:resource="#c1"/>
</skos:Concept>

<skos:Combination rdf:about="#c1">
  <skos:combinationMember rdf:resource='#spain'/>
  <skos:combinationMember rdf:resource='#town'/>
</skos:Combination>

<skos:Concept rdf:about="#spain">
  <skos:prefLabel xml:lang="en">Spain</skos:prefLabel>
  <skos:useInCombination rdf:resource='#c1'/>
</skos:Concept>

<skos:Concept rdf:about="#town">
  <skos:prefLabel xml:lang="en">Town</skos:prefLabel>
  <skos:useInCombination rdf:resource='#c1'/>
</skos:Concept>

Here I introduced the class Combination and the properties
useCombination and useInCombination. So you can also add notes and
documentation two Combinations if its a class.

Is anyone using SKOS Mapping in real life? It's just a theoretical
sketch, isn't it? Is it used in any working information retrieval system?

Oh, I just found this thread about the same issue (but without a
proposed solution?):
http://lists.w3.org/Archives/Public/public-esw-thes/2006Jun/0006.html
How about using the wiki instead so always have the latest version of a
discussion?

Greetings,
Jakob

P.S: Sorry for my cheeky comments - I just left university with a master
in computer science and library and information science confronted now
with the reality of standards and it's usage ;-)
Received on Monday, 17 July 2006 15:29:49 UTC

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