SV and Thesaurus - decide

[Rob Seaman]

On Sep 21, 2007, at 7:14 AM, Ed Shaya wrote:

> 	I guess it is time again to explain the OWLViper tool, to make a  
> clear use case for vocabularies and vocabulary extensions and  
> vocabulary translations.

My previous question about use cases sank without a trace.  Perhaps I  
can try again.  Here you are making a "case for using this tool", not  
asserting a use case.  Before learning to use a tool, one needs to  
know, as Edwin Starr says:  What is it good for?

> 	We have a tool that reads in OWL ontologies and creates a menu of  
> objects to choose from.  You can grab AstroObjects and place them  
> on the canvas.  Then you can choose properties  of these objects  
> (like "hasMeasurement RotationalVelocity" or "hasPart Halo" or  
> "hasStar Cepheid") and add them inside the object's box.  Then you  
> can constrain values by min and max or contains string.  It can  
> then query for these objects or, if it already has data, it can go  
> on to perform operations on the data.  But, lets focus on query.

Several times during this discussion folks have indicated that such  
ontologically aware tools are useful in various other fields that are  
parsecs ahead of astronomy in this regard.  Let's get past that.  In  
what *specific* ways can these great tools be used to accomplish  
astronomical chores - whether big or little?

> 	The best situation (from the application's point of view) is for  
> all datacenters to have exactly the same ontology and able to  
> respond to requests for OWL subclasses.

This sounds to me like you are making Rick's point.  The VO focuses a  
lot of attention on something we call "queries".  Astronomers are  
usually, rather, pursuing statistically meaningful sample selection.   
A query is a means to an end.  Does introducing tolerance for human  
fuzziness of expression aid or hinder the astronomers' quest?

> 	It would be nice if we all used the same standard vocabulary, but  
> that may not be the case.  What if each datacenter has its own  
> ontology?

Are the "domain practitioners" in other fields ever required to  
understand - or ever even read - the word "ontology"?  Samuel Johnson  
and endless generations of school teachers have made the word  
"vocabulary" a familiar friend.  The word "ontology" is as opaque  
today as it was to Johnson himself:

     ONTOLOGY:  The science of the affections of being in general;  
metaphysicks.

There is some reason that ontologies have been hanging fire in the  
VO.  Is it simply crass unfamiliarity?  Or is it perhaps that our  
needs differ from other communities?  Obviously there is pent-up  
interest in resolving this issue.  Folks aren't sending these  
messages to the semantics list (and certainly aren't subscribed to  
the list in the first place) to just chat - we'll have plenty of that  
next week.  Rather, the word "ontology" came up at the first VOEvent  
workshop as some promethean technology that would (eventually) help  
us to resolve all ambiguities and shadings of meaning and to close  
the gap between harsh machine representations and the subtle  
gradations of human expression.

	1) Can ontologies deliver this?
	2) Do astronomers need this?

This reminds me of the "to STC, or not to STC" debate.  Space-time  
coordinates are clearly intrinsic to the practice of astronomy.  What  
can we do to resolve the same question regarding ontologies?

- Rob