UCDs vs ontologies?

[Elizabeth Auden]

> On the other hand, we're told that the role of UCDs is distinct from that of 
> ontologies.  An ontology is an (attempt) at expressing the complete range of 
> some knowledge domain.  Astronomy is a big subject - its ontology will be 
> big.

> Personally, I think the VO community will need to develop several separate 
> ontologies over time as well as several separate glossaries of UCDs or 
> UCD-like constructs.  It is not obvious that a glossary of UCDs for tabular 
> convenience is equivalent to a glossary of UCDs for VOEvent convenience.  An 
> ontology can afford to be large and unwieldy to reach its goal of being 
> complete and accurate.

Incidentally, I've posted a first go at a VOEvent ontology (OWL-DL format) 
on the VOTech wiki at 
http://wiki.eurovotech.org/bin/view/VOTech/VoEventOntology. Any comments 
on the structure, concepts, and coverage of this v0.000000001 ontology 
would be appreciated.

cheers,
Elizabeth