[fitswcs] Re: WCS activity

[Don Wells]

Dear Mark, FITS committee officers and other friends of WCS,

There are two models which could be used to produce FITS standards:

Model A) The FITS committees could operate by a fixed set of rules
         which would specify definite timetables for proposing and
         deciding on revisions and for making the final accept/reject
         decisions on proposed standards. Most discussion would be
         public.  Supermajorities of 2/3 or 3/4 YES would approve
         proposals, and dissent expressed as NO and ABSTAIN votes
         would be considered normal.

Model B) The FITS committees could operate by a combination of public
         discussion and private quiet negotiations (mostly one-on-one)
         with the goal of obtaining a [nearly] unanimous consensus on
         every FITS agreement, so that agreements will be accepted and
         implemented universally in astronomy. NO and ABSTAIN votes
         would be rare, because negotiation would usually continue
         until they become YES votes.  Much time and private
         negotiations would be used to uncover and resolve vague
         private feelings of unease.

Model B is what we have currently, with me as IAU-FWG Chair.  Model B
was also a good description of FITS standards procedures during the
period when Preben Grosbol was IAU-FWG Chair, when we produced the
BINTABLE Agreement in a process that lasted about seven years from
initial idea to final publication.

Model A is what I perceive Mark to be advocating. I sympathize with
his frustration as one of the principal authors of the WCS papers, who
has seen the final approval and publication of his work be delayed
again and again over nearly a decade.  It is understandable that he
would be an advocate of some version of Model A.

I am a proponent and practitioner of Model B because I believe that it
is the best policy for creating permanent universal data format
standards for astronomy research.  I expect that some mixture of the
Model A and Model B policies would probably be better than either pure
A or pure B, but I am currently unsure about the optimum relative
weight. I would like to hear more opinions on this question.

Mark Calabretta writes:
 > ..We called time and again for people to evaluate the proposal and
 > respond if they found it to be lacking for their instruments.  In
 > fact, the first few drafts of paper III explicitly called for
 > examples of instruments for which coordinate description would be
 > difficult..

Sigh... the people who need to make these responses regarding their
instruments are often very busy, and often they are unsure what to
say. Often the key design people are not on our mailing lists, and we
must search for them and persuade them to join our process. Often
their institutions and projects have priorities and timetables which
are inconsistent with our standards process.  If we wait for such
responses for a specified period of time, and then declare the issues
settled even though we have not received the input, we may indeed
produce and publish FITS standards documents in a neat, organized
fashion, but we are unlikely to produce the [nearly] unanimous
consensus which leads to [nearly] universal implementation and
interoperability.  Twenty years of experience in developing FITS
standards can be summarized with the assertion that private
negotiation must be used to achieve the latter result.

 > .. the BoF voted to promote the papers past the general discussion
 > stage to ratification by the regional committees..

That vote meant that there is general acceptance of most of content of
the three WCS draft documents as standards. I.e., we are very close to
achieving the goal of Model B.  Because of the general acceptance
demonstrated by that BoF vote, I believe that if the WCS-I and WCS-II
documents had been put to a vote six months ago, they would have
passed in the three regional committees and the IAU-FWG with almost no
discussion and probably with no NO votes.  However, our committees
might then have been embarrassed to find that WCS-I needs
modifications to support WCS-III.5.

Regards, 
Don      [current Chair, IAU FITS Working Group]
-- 
  Donald C. Wells      Scientist - GBT Project        dwells at nrao.edu
                    http://www.cv.nrao.edu/~dwells
  National Radio Astronomy Observatory                +1-434-296-0277
  520 Edgemont Road,   Charlottesville, Virginia       22903-2475 USA