Re: Vocab AND Ontology?

> I'd like to propose, if it is feasible, a way forward on the issue of
> creating an SV.

I think that Tony's effort to reconcile the different points of view emerging from the discussion, and at the same time to propose a practical way to go on working, is greatly appreciable. I see only a couple of points to clarify to remove possible ambiguities.

First, I think we should shape and trim our effort having in mind not only the what, who and how addressed by Tony, but also which are our final goals in terms of IVOA Recs. If we agree that what we need is both a Standard Vocabulary and an Ontology, we probably have to think of two subsequent but distinguishable IVOA documents. This just out of methodology. This even in the case where the list of concepts (Ontology) should coincide with the list of SV terms. This even in the case we thought of the SV as a sort of by-product of the Ontology.

Second. It is clear from the discussion that the approach proposed in the draft is not convincing the majority of the active members of the WG. I'm not referring here to the format (XML or other) but to the content of the SV: tokens to be assembled in an UCD-like way to express astronomical concepts. The advantages were (are! :-) ) : a) we know already how to deal with UCDs; b) slower rate maintainance / up-grade; c) the proposal is there, the SV could be used now. The main (if not the only) disadvantage was (is) the absence of ontological structure (obvious, they are tokens, not concepts!) and the need to start all over again, should we decide to go for a Vocabulary and then an Ontology.

Changing tokens into concepts, using as our starting point the IAU Thesaurus has no great disadvantages, because the Thesaurus can be rapidly up-graded with a handful of concepts, and we have already the basic relationships BT, NT, etc. if we want to go on with an Ontology.

I think to correctly interpret the feelings of the authors of the draft (please correct me if I got them wrong!) saying that we don't object changing terms into concepts. It can even be simpler for users/tools of other WGs to use them.

As Tony said, a group appointed by the WG can then write a new draft, say on "The IVOA Standard Vocabulary" in one or two months. We will be only on the first step of the ladder, to cite Norman, and we whould probably want to formalize this first step within the IVOA. If we think we are satisfied with this, we can stop here and talking about formats could be a waste of time.

If, on the other hand, we think we have to climb the ladder (I personally think so) we can at the same time put together people and efforts around another draft, and start climbing further. With no hurry. There wan't be the risk that other WGs define their own SV, and the IVOA being tranformed into a Tower of Babel. The SV will be already there, in its status of WG-agreed, Rec-to-come document.

Cheers,
Andrea

Andrea Preite Martinez                 andrea.preitemartinez-at-iasf-roma.inaf.it
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