How to choose?

[Tony Linde]

I'm not too sure what you're arguing for/against, Rob. For consensus - I
agree but noted dubiety. For more time to discuss this - I agree but others
think we need an SV *now*. Against using one method for all problems -
definitely but I call to mind past history of IVOA (I'm only surprised
no-one has proposed VOTable for the SV). For a set of use cases - I agree
and have called for them before [1]. For further study of Frost -
absolutely.

As far as I'm concerned this aspect of the threads is simply about which
technology to use for the SV, not about what the whole area of semantics
might mean to the whole area of the VO.

[1]: I've created a couple of new wiki pages (see links from
http://www.ivoa.net/twiki/bin/view/IVOA/IvoaSemantics#Standard_Vocabulary)
in which we can define use cases and the scope of the SV. Maybe populating
these will help reach consensus.

T.

> -----Original Message-----
> From: owner-semantics at eso.org [mailto:owner-semantics at eso.org] On
> Behalf Of Rob Seaman
> Sent: 25 September 2007 09:04
> To: semantics at ivoa.net
> Subject: Re: How to choose?
> 
> On Sep 24, 2007, at 2:08 PM, Tony Linde wrote:
> 
> > Okay we seem to have equally good arguments from both sides of the
> > fence:
> >
> > a. develop vocab using SKOS and leave the ontology unless someone
> > else wants to do that in parallel, or
> >
> > b. develop vocab using OWL and derive SKOS version.
> 
> While I'm pleased with the traction this conversation is getting, I
> don't actually think we have coherent arguments yet for either side
> of the fence.  Robert Frost says:
> 
> 	"Something there is that doesn't love a wall,"
> 
> But his neighbor (in "Mending Wall") says:
> 
> 	"Good fences make good neighbors"
> 
> Google this and you'll see 1,120,000 hits, most relying on Frost's
> quote to assert things like:
> 
> 	"Well-defined borders help prevent ethnic tension."
> 
> But the poet, of course, meant exactly the opposite:
> 
> 	"'Why do they make good neighbors? Isn't it
> 	Where there are cows?
> 	But here there are no cows.
> 	Before I built a wall I'd ask to know
> 	What I was walling in or walling out,
> 	And to whom I was like to give offence.
> 	Something there is that doesn't love a wall,
> 	That wants it down.' I could say 'Elves' to him,
> 	But it's not elves exactly, and I'd rather
> 	He said it for himself."
> 
> Alan Weisman's excellent book, "The World Without Us", gives a sense
> for exactly how long all those walls would last without continual
> mending:  Not long.
> 
> > It seems that more people, of those who are knowledgeable and care,
> > prefer the SKOS approach.
> 
> Is this really an issue to take a poll on?  For astronomical
> purposes, consensus should be based on astronomical use cases.  Which
> of SKOS, OWL, something else (e.g., UCDs, SV as in the current draft,
> etc.) - or of natural language, the "none of the above" option - is
> best for VO purposes?
> 
> Is there even some reason to believe that all VO purposes (a pretty
> broad expanse of human intent) map onto the same semantic paradigm?
> Since much of the motivation for SV as we know it came from VOEvent,
> which of these options is best for the narrower VOEvent use cases?
> 
> > Can some of those 'knowledgeable' people get together this week and
> > really thrash out the options - maybe each person who favours one
> > side has to argue for the other side.
> 
> How about we all argue for the same side - for the efficient
> realization of useful astronomical goals?  Do we even care about the
> "best" solution?  Aren't we really engaged in an exercise of
> "satisficing" (http://utilitarianism.com/satisfice.htm)?
> 
> > Otherwise, about all I can suggest is that we leave the line open
> > to arguments for the rest of this week and then call for a vote
> > next week - unless some miracle occurs (http://news.bbc.co.uk/2/hi/
> > uk_news/england/london/7010409.stm) and consensus breaks out.
> 
> What possibly would be the advantage of calling for a vote in the
> absence of consensus?  I don't know what passes for a miracle in the
> rest of the VO, but this really doesn't seem that intractable an
> issue compared to some others on which VOEvent has reached consensus.
> 
> I'm also a bit perplexed what exactly would be voted upon.  As we've
> been reminded, RDF, SKOS, OWL are already perfectly respectable
> standards. What precisely is keeping one VO project or another from
> using ontologies?  On the other hand, a standard IVOA vocabulary
> list, for instance, would be a data product held in common that
> requires sign off from the hierarchy.  An assertion that "we don't
> need no stinkin' vocabulary" does not imply "we need to pick between
> SKOS and OWL".
> 
> A few questions:
> 
> - What happens when the ontology evolves?  After all, we're talking
> about methods for discovering and characterizing brand new
> phenomena.  (http://www.urticator.net/essay/2/217.html)
> 
> - How efficient are the tools of different kinds for applications
> with split second timing requirements?  (http://alphard.ethz.ch/
> gerber/approx/default.html)
> 
> - How robust are they against network or server outages?  KPNO has a
> policy against mountain data-taking systems depending on network
> resources for critical functionality.  Presumably the corresponding
> policies for robotic networks are even more strict.
> 
> - What can SKOS and OWL do for simple use cases?  For example:
> 
> 	1) A high signal-to-noise optical transient is detected.
> 
> 	2) A VOEvent packet is generated.
> 
> 	3) Its discovery "signature" is compatible with a wide range of
> possible underlying phenomena.
> 
> 	4) Its brightness, location, rarity, etc., make it of interest to
> several subscribers.
> 
> 	5a) How do semantic technologies aid in the efficient and
> reliable
> characterization of the phenomenon?  (http://
> oaei.ontologymatching.org/2007)
> 
> 	5b) What strategy is best used by the several subscribers to work
> together compiling follow-up observations for the common good?
> (http://www.iscid.org/encyclopedia/Nash_Equilibrium)
> 
> - Would SKOS or OWL (or SV, for that matter) perform better than the
> status quo (natural language)?  (http://en.wikipedia.org/wiki/
> Impedance_matching)
> 
> - If this is not a well posed use case for differentiating between
> our semantic software choices, then what would be?  (http://
> www.econlib.org/Library/Enc/TragedyoftheCommons.html)
> 
> - Rob