utype questions

[Norman Gray]

Doug, hello.

On 2009 Jun 30, at 01:50, Douglas Tody wrote:

> That would probably work within the context of the ontology and its
> tools.  What happens when the user inputs the string "quasar" or
> "agn"?  That is, how do we map user input to this URI;

This is a key point.  You can do this in a quick and dirty way by  
simply searching through the labels in an ontology looking for the  
string "quasar".  Doing a better job than that isn't trivial, but we  
currently have a service which does that, available either through a  
web page or as an XML-RPC service.  See <http://explicator.dcs.gla.ac.uk/WebVocabularyExplorer/ 
 > (thanks to Alasdair Gray for the initial version, and Stuart  
Chalmers for keeping it going and developing it).  This, incidentally,  
uses the vocabulary terms, rather than the CDS OAOT.

Such a service also lets an interface say 'You've mentioned AGN, do  
you mean more specifically 'LINER" or Radio Loud/Quiet AGN?'  That is,  
the goal here is to make the user experience better, and help the user  
provide better metadata.

Looking at the relevant parts of the four Vocabularies document  
vocabularies, I see links back and forth to quasar absorption/emission  
lines, blazars, seyferts, BL Lac objects, compact nuclei, double  
quasars, X-ray quasars, quasar microlensing, high/low states, and  
more.  Having applications use all that is just a matter of imagination.

> can we defer
> this translation?.  Later when we want to review the data model and
> display the object classification to the user what do we do to get
> a simple string for display purposes? (e.g. in a table of objects).
> Is there any good reason to not defer the translation until the
> ontology tool is used?

I don't think there's a specific ontology tool being talked of.  The  
application context might be a resource registration, or a pop-up in  
VOExplorer, or any of a number of things.  And the reason we can't  
defer it is that the user won't be there forever, and they're the only  
entity that can help get from the world of strings into the world of  
concepts.

All the best,

Norman




> On Mon, 29 Jun 2009, Matthew Graham wrote:
>
>> Hi,
>>
>> In that case, just use the Ontology of Astronomical Object Types  
>> that has been produced;
>>
>> http://www.ivoa.net/internal/IVOA/IvoaSemantics/WD_2007-02-19.pdf
>>
>> To refer to an AGN use "http://eurovotech.org/objects-structure.owl#AGN 
>> "
>>
>> This has subclasses:
>>
>> "http://eurovotech.org/objects-structure#LINER"
>> "http://eurovotech.org/objects-structure#RadioLoudAGN"
>> "http://eurovotech.org/objects-structure#RadioQuietAGN"
>>
>> which in turn have more subclasses.
>>
>> 	Cheers,
>>
>> 	Matthew

-- 
Norman Gray  :  http://nxg.me.uk
Dept Physics and Astronomy, University of Leicester, UK