Astronomical vocabulary explorer
norman at astro.gla.ac.uk
Thu May 8 11:09:38 PDT 2008
On 2008 May 3, at 16:28, Franck Le Petit wrote:
> We are building a vocabulary that will be used in the Simulation
> Datamodel. Semantics is required for several "keywords":
> - Physical processes
> - Algorithms
> - Simulated Object
> - ...
> May you tell me what is the best way to implement this ? Should we
> do .RDF files ? And if yes, is there any tool to do it easily, I
> mean to facilitate the entries and the relationships between words ?
The semantics group is currently discussing a document which aims to
give precisely this sort of advice.
The current Working Draft document is at
and the current "editors' draft" lives at
(I've just today released a fairly significant update to that).
Summarised, it says that yes, RDF is good for this, and that
specifically there's a framework called SKOS, which is intended to
support precisely this sort of vocabulary. I'd be very keen to hear
your comments on the intelligibility and user-friendliness of this
document, if you have time.
Vocabularies are at the lightweight end of the ontology spectrum, and
SKOS vocabularies in particular are concerned with rather thin
semantics such as which terms are broader or narrower in scope than
others. The sort of ontologies that Ed is talking about are more
expressive -- you can do more with them -- but they're correspondingly
more expensive to create and broker agreement on.
The most practical approach, I think, is to find a vocabulary that is
reasonably close to what you need, and use that as much as possible.
Creating a vocabulary (or ontology, or schema, or DTD) is easy;
creating one that a useful number of other people agree on is very hard!
The vocabularies that are distributed with the above WD (a snapshot of
which you can download as a bundle at <http://www.astro.gla.ac.uk/users/norman/ivoa/vocabularies/rdf/vocabularies-2008-05-08.tar.gz
>) were generally produced by starting with an existing vocabulary in
some semi-regular format, and writing a per-vocabulary script to
regularise that into RDF. That is, we didn't actually need to use a
GUI tool at any point, though I'd agree with Ed's remarks about the
appropriateness of Protégé.
Norman Gray : http://nxg.me.uk
Physics and Astronomy, University of Leicester
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