> Just to show you that you are not the only one "uneasy" with somebody
> else's point of view, I'll make an example of how "uneasy" could feel
> an
> UCD-folk like me.
> Take for instance the UCD you proposed few days ago:
> instr.obsty.site;weather.seeing just to express "seeing"
>
> When I saw it I made a jump on my chair: why?
> In inverse order of importance:
>
> 1. The UCD-like syntax is wrong: first the "quantity", then the
> "qualifier"
> it should read: weather.seeing;instr.obsty.site
Sorry - I confess that I haven't been worrying AT ALL about things like
order, since
the examples I've been worrying about don't depend upon it: is there
really a
fundamental difference between "seeing at an
observatory"=weather.seeing;instr.obsty.site
and "observatory's seeing"=intr.obsty.site;weather.seeing. Maybe for
some extreme
examples and onotolgy folks, but otherwise......
> 2. We are proposing UCD-words, not UCDs. If you propose an independent
> word
> for "seeing", ok, it's :weather.seeing
True, but my bottom line is how to use them to express something. The
UCD words
are defined not just to be there but to be used. I forgot to
distinguish between words
and atoms - excuse moi!
> 3. My mind works in terms of "how to assign ucd-words starting from a
> description, and then build an UCD" e.g. in term of the process to
> build an UCD from one or more keyword(s):
> the "keywords => ucd-words => UCDs" chain.
> It is impossible (in this framework) to go from the single keyword
> "seeing" to an UCD composed of two UCD-words
> (each one of these UCD-words needs its own description).
Hmmm.... don't quite get that. My approach has been
> Let's reverse the roles: you jump on the chair when you see the
> description
> of the src.class.* words.
> You are perfectly right. What is not said is that I do not use the
> description
> field to assign words/ucds: I use a series of words (keywords
> derived from the description) that are OR-ed,
> which is exactly equivalent to the loosier description you suggest.
Sorry - still don't get this..... Are you saying that
src.class.richness DOESN'T mean
Abell class (even though that's what the official list says) or not?
If it DOES mean
that, then we need to rename the word. If it DOESN'T mean that, we
need to change
the description. Either way, we need to change something, because
leaving it as
it is will forever prevent someone from using richness for anything
else with
a good conscience. It's perfectly valid for someone to suggest a word
based on their
own needs (indeed, this is the BEST way), but the UCD community should
make sure
that the necessary generalizations are made when needed, and in the
case of my
list, I feel they are needed.
> As I already said, the ucd vocabulary is not only composed of words
> that are "quantities". More and more "objects" are creeping in, and I
> can
> imagine the development of two sub-lists :
>
> a "q-list" slowly evolving (or even stabilized; after all the number of
> new (astro-)physical quantities per year is probably very easy
> to control!!)
>
> and an "o-list" (or whatever name we decide for it!!) for
> "non-quantities",
>
> both lists with the same syntax (just for simplicity and
> "interoperability" (!!),
> so that we can continue to build UCDs of the form:
>
> word[q-list];word[o-list] ...
>
> as we do today without knowing that we are actually doing it (!)
I'm have been arguing for exactly this solution, but I have been getting the impression that others aren't so happy with it.
I've trimmed down the VOConcept list to a bit more than 100
words/compositions
to include only those which are needed by VOEvent. I'd be very happy
to add "syntax codes"
and formal descriptions, trim the list even further, mail everyone a
down-to-earth ASCII file, and
drop the whole issue of XML Schema integration if the UCD community
would absorb VOConcept.
Rick
Dr. Frederic V. Hessman Hessman-at-Astro.physik.Uni-Goettingen.DE Universitaets-Sternwarte Tel. +49-551-39-5052 Geismarlandstr. 11 Fax +49-551-39-5043 37083 Goettingen http://www.uni-sw.gwdg.de/~hessman ------------------------------------------------------------------------ -------------------------
http://monet.uni-goettingen.de ------------------------------------------------------------------------ -------------------------Received on 2005-06-15Z09:22:35