Thank you for making this point Tony. There is a distinction between UCD
semantics (content description) and UCD syntax (combination of word
hierarchies) that should be made explicit.
> I've always seen UCDs as like data types. They are applied to columns and
> describe what type of data is in the column - so they are data types. Much
> the same as 'float', which I guess you could call number.float;32bit
Yes. That is the right way yo think of UCD.
> In which case GRB is not really relevant as a UCD, nor is
> process.variation.burst;em.X-ray.
We are trying to be careful to talk of "controlled vocabulary" and "UCD syntax". Your example is not a datatype or a UCD. Rather it is a piece of controlled vocabulary expressed in a UCD-like syntax.
> So unless UCDs are now going to be turned into the new astro thesaurus or
> a type of astro ontology, it doesn't seem to make sense to have a UCD for
> GRBs.
Thesaurus and Ontology imply a set of nodes and relations between them. At the moment we are just building the nodes, i.e. the controlled vocabulary. We could in the future build more structure.
Roy Received on 2006-05-18Z04:13:05