What use the AstroOntology

Mon Mar 5 15:30:13 PST 2007

Roy,
	It is probably best to have in the ontology all of the commonly used 
aliases of all terms so that we are free to express ourselves in a wide 
variety of ways.

Ed

 From The Tractatus by Ludwig_Wittgenstein
# The world consists of independent atomic facts — existing states of 
affairs — out of which larger facts are built.
# Language consists of atomic, and then larger-scale propositions that 
correspond to these facts by sharing the same "logical form".
# Thought, expressed in language, "pictures" these facts.
# We can analyse our thoughts and sentences to express ("express" as in 
show, not say) their true logical form.
# Those we cannot so analyse cannot be meaningfully discussed.

Roy Williams wrote:
> Kirk
> All of what you say about tags and tagging and tag-clouds is true. 
> However, social sites like Flickr and Blogspot use unconstrained tags 
> (i.e. whatever you like), and they have millions of users. So perhaps 
> the Virtual Observatory could save a lot of effort by allowing 
> unconstrained tagging? Thus a VOEvent that is a supernova could be 
> tagged "SN" or "supernova" and everyone would be perfectly happy?
> Roy
> 
> 
> 
> kborne at gmu.edu wrote:
>> In addressing the subject question, I like to think of ontologies
>> as useful for search and discovery (of metadata and data).  The
>> application of ontologies in the social networking sense (i.e.,
>> tagging and folksonomies) allows researchers to tag scientifically
>> useful data (and metadata) by the science application area (e.g.,
>> AGN research, or QSO research) in which they found it to be
>> applicable.  This assertion does not mean that this tag is correct or 
>> universally acceptable, but it means that someone
>> found it useful to describe a particular IVOA resource.  In this
>> context, some future researcher may then search for similarly tagged 
>> items for their own research (which they may accept or reject
>> according to their own scientific needs and/or current 
>> understanding).  None of this imputes a greater meaning to the tag 
>> than that of a single term within a larger scientifically meaningful 
>> tag cloud.
>> Tag clouds provide validation of the tags through repeated assertions
>> of that tag to describe a particular resource (hence, the tag appears
>> in a larger font presentation than the other tags).  Implementing these
>> assertions and these IVOA resource search & discovery capabilities is 
>> made easier through the AstroOntology (OWL or RDF triplets or whatever).
>>
>> - Kirk Borne
>>   George Mason University
>>   http://classweb.gmu.edu/kborne/
>>
>>
>>  
>>> From: "Tony Linde" <Tony.Linde at leicester.ac.uk>
>>> To: "'IVOA semantics'" <semantics at ivoa.net>
>>> Subject: What use the AstroOntology Date: Sun, 4 Mar 2007 11:19:55 -0000
>>>
>>> I won't even attempt to enter the astronomical discussion of QSOs and 
>>> AGNs,
>>> but do wonder if we're conflating two different approaches here: an
>>> AstroOntology and sets of identification rules.
>>> The AstroOntology is a set of terms used in astronomy and the relations
>>> (is-a-type-of, is-a-component-of, ...) between them.
>>>
>>> OTOH there will be numerous sets of identification rules for each of the
>>> terms: such as the ones being discussed here for QSOs and AGNs. The 
>>> rules
>>> may also be context driven: in context A the rules are this set while in
>>> context B they are another set.
>>>
>>> It seems to be that the ontology changes relatively infrequently 
>>> while the
>>> rules (at least for terms on the fringe of the ontology) change much 
>>> more
>>> frequently.
>>>
>>> An ontology would be hideously inefficient at the job of identifying 
>>> objects
>>> from a set of observations. I'm not even sure it would be possible 
>>> given the
>>> limited ability of OWL to contain identification rules to the depth 
>>> needed
>>> for QSO vs AGN. I think any putative use of an AstroOntology to infer
>>> objects from observations is doomed to fail.
>>>
>>> We have to ask what we want to use an ontology for. Then decide if the
>>> structures of OWL are up to the job. The QSO/AGN discussion seems to 
>>> show
>>> that any definitions added to the ontology need to be limited and for
>>> guidance only: they cannot serve as identification rules.
>>> At least, I don't think they can. Can they?
>>>
>>> Cheers,
>>> Tony.
>>> -- 
>>> Tony Linde
>>> Phone:  +44 (0)116 223 1292    Mobile: +44 (0)785 298 8840
>>> Fax:    +44 (0)116 252 3311    Email:  Tony.Linde at leicester.ac.uk
>>> Post:   Department of Physics & Astronomy,
>>>         University of Leicester
>>>         Leicester, UK   LE1 7RH
>>> Web:    http://www.star.le.ac.uk/~ael
>>>
>>> Project Manager, EuroVO VOTech   http://eurovotech.org Programme 
>>> Manager, AstroGrid     http://www.astrogrid.org  
>>>
>>> http://www.Taglocity.com Tags: IVOA, semantics
>>>     
>>
>> ----------------------------------------------------------------------------- 
>>
>> Dr. Kirk D. Borne
>> NASA Goddard Space Flight Center, SSDOO Program Manager, Perot Systems 
>> (ex-QSS)
>> and George Mason University, Associate Research Professor, College of 
>> Science
>> <mailto:kirk.borne at gsfc.nasa.gov>  Tel. +1-301-286-0696  Fax: 
>> 301-286-1771
>> Staff page:      http://rings.gsfc.nasa.gov/
>> US Virtual Observatory:  http://www.us-vo.org/
>> Large Synoptic Survey Telescope:  http://www.lssto.org/
>>
>>   
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