RE: SKOS & SIMILE, concepts, terms, URIs, mappings

Hi Mark, 


> Here is the use case we had in SIMILE:
> 
> I have some Artstor data that uses the term "cadavers" (which 
> is a preferred
> term in the Artstor data), and I want to map onto the LOC TGM 
> thesaurus. In
> LOC TGM, cadavers is an alternative term for both "dead 
> animals" and "dead
> persons". Therefore, my guess is LOC decided that the term 
> "cadavers" was
> ambiguous, so they decided to encourage cataloguers to use 
> the two less
> ambiguous terms. However here the concept corresponding to cadaver is
> actually the union of the concepts that have "dead animals" and "dead
> persons" as their primary terms. 

So taking this as an example, using the following hypothetical RDF
descriptions of the concepts involved ...

  <skos:Concept rdf:nodeID="a">
    <skos:prefLabel>Cadavers</skos:prefLabel>
    <skos:inScheme rdf:nodeID="Artstor"/>
  </skos:Concept>
  
  <skos:Concept rdf:nodeID="b">
    <skos:prefLabel>Dead animals</skos:prefLabel>
    <skos:altLabel>Cadavers</skos:altLabel>
    <skos:inScheme rdf:nodeID="LOCTGM"/>
  </skos:Concept>
  
  <skos:Concept rdf:nodeID="c">
    <skos:prefLabel>Dead persons</skos:prefLabel>
    <skos:altLabel>Cadavers</skos:altLabel>
    <skos:inScheme rdf:nodeID="LOCTGM"/>
  </skos:Concept>

... using the most recent version of the SKOS-Mapping schema [1][2] the
Artstor -> LOCTGM mapping would be expressed as ...

  <rdf:Description rdf:nodeID="a">
    <skos-map:exactMatch>
      <skos-map:OR>
        <skos-map:memberList rdf:parseType="Collection">
          <rdf:Description rdf:nodeID="b"/>
          <rdf:Description rdf:nodeID="c"/>
        </skos-map:memberList>
      </skos-map:OR>
    </skos-map:exactMatch>
  </rdf:Description>

... and the LOCTGM -> Artstor mapping would be expressed as ...

  <rdf:Description rdf:nodeID="b">
    <skos-map:broadMatch rdf:nodeID="a"/>
  </rdf:Description>
  
  <rdf:Description rdf:nodeID="c">
    <skos-map:broadMatch rdf:nodeID="a"/>
  </rdf:Description>

This is of course a semantic mapping, and needs a person to identify it.  

Some sort of mapping tool is what I had in mind as a UI, to help a user
define semantic mappings (possibly suggested by lexical mappings).

As a totally hypothetical example, I was thinking that lexical mappings
could be expressed as in e.g. ....   

  <test:AltToPrefLabelMatch>
    <test:source rdf:nodeID="b"/>
    <test:target rdf:nodeID="a"/>
    <test:stringMatch>Cadaver</skos-map:stringMatch>
  </test:AltToPrefLabelMapping>

I would love to see another round of development on the SKOS-Mapping schema
(I think it needs it), with some proper test cases to try it out.  I don't
think we have this effort left in SWAD-E though, something to think of for
the future :).

Yours,

Alistair.

[1] http://www.w3c.rl.ac.uk/2003/11/21-skos-mapping
[2] http://www.w3c.rl.ac.uk/SWAD/deliverables/8.4.html


---
Alistair Miles
Research Associate
CCLRC - Rutherford Appleton Laboratory
Building R1 Room 1.60
Fermi Avenue
Chilton
Didcot
Oxfordshire OX11 0QX
United Kingdom
Email:        a.j.miles@rl.ac.uk
Tel: +44 (0)1235 445440