WDTS SKOS thesauri

This page is meant to host the discussion on the Water Data Transfer Standards SKOS thesauri kindly contributed by Brad Lee. It will cover suggestions for improvement, proposals for harmonisation with other thesauri, and everything that can help leveraging the resource in AIP-3 pilots. The repositories are comprising 24 distinct concept schemes:
  • Coordinate Systems BoM code Scheme
  • Quality Code Scheme
  • Position method code Scheme
  • Regulation Parameter Scheme
  • obs-condition code Scheme
  • EPSG Water Quality Sampling Depth code Scheme
  • Organisation Scheme
  • Unit Of Measure Scheme
  • BoM Cordinate Reference System code Scheme
  • Security Scheme
  • BoM Water Quality Sampling Depth code Scheme
  • Transaction method code Scheme
  • Coordinate Systems EPSG code Scheme
  • Survey code Scheme
  • Conversion Interpolation type code Scheme
  • Position method code Scheme
  • Status Scheme
  • Axes EPSG code Scheme
  • Parameter Scheme
  • Interpolation type code Scheme
  • Sampling Parameter code Scheme
  • Processing code Scheme
  • arcroles code Scheme
  • EPSG Cordinate Reference System code Scheme


Adding inferred statements

The thesauri do not contain inferred statements, that is, if term A is linked to term B by property skos:narrower, term B should be linked (according to the semantics of OWL) to term A by property skos:broader (and vice versa). This is supposed to be automatically inferred by the system but, unfortunately, most RDF storage systems do not handle this (e.g., Sesame does not handle this out of the box).
As a consequence, it is convenient to provide these inferred statements explicitly so that one can choose whether to include them in the knowledge base (if the system does not compute OWL entailments) or not. The file enlarged-skoscore.rdf attached below provides these statements; the file enlarge-skoscore.xsl is the stylesheet that has been used to create them. The stylesheet iteratively loads the files (that is, can be applied to any of the files indifferently) and computes the statements.

Alternative organisation of the thesauri

As mentioned earlier, the repository comprises 24 distinct concept schemes, many of which only has a handful of terms that are related to a common super-concept by property skos:broader. It would be possible to render them as a single concept scheme (say, the "WDTS thesaurus") and use SKOS collections for grouping terms according to the distinct components listed above. This would allow for using the SKOS matching properties (e.g., skos:narrowMatch) exclusively for harmonising the thesaurus with other thesauri.

Property instances requiring modification

Some terms are related to terms in different concept schemes by property skos:related (e.g., "Ground Water Level" in the Parameter scheme and "Metres" in the Unit Of Measure Scheme) while this property is only meant to link terms in individual concept schemes (skos:relatedMatch should be used instead). The skos:related property would be fine in the alternative organisation suggested above.

Cristiano Fugazza,
May 11, 2010, 12:42 AM
Cristiano Fugazza,
May 11, 2010, 12:42 AM