Subject: Moved & Seconded (was Re: FITS checksum proposal)

From: dwells at nrao.edu (Don Wells)
Date: 05 Jan 1995 23:54:15 GMT

It appears to me that Rob Seaman's checksum idea has been
independently implemented by both him and Bill Pence, and that Pence
has joined Seaman in advocating this idea for general adoption by the
FITS community. I therefore conclude that, in the spirit of Robert's
Rules of Order, this is a motion which has been moved and seconded,
and is now ready for discussion.  I have placed copies of the postings
by Seaman and Pence into the FITS archive as the two files

    ftp://fits.cv.nrao.edu/fits/documents/proposals/checksum{1,2}.news

I recommend that chairpersons and members of the various regional FITS
committees consider this proposal for possible adoption as a standard
and/or recommended practice in the FITS community.  In particular, the
WGAS FITS Committee should consider the checksum proposal, because it
was developed within the WGAS (North American) region.

                -*-

Newcomers to the FITS world should know that the procedure for
creating FITS standards has been deliberately designed to be slow and
tedious, with multiple stages of review and multiple formal votes.  We
require multiple implementations with demonstrations of
interoperability _before_ the formal votes. Our cumbersome protocols
are necessary because we expect FITS standards to survive for _decades_.

Suppose that one or more members of the WGAS FITS Committee (see
ftp://fits.cv.nrao.edu/fits/documents/committees/aas_wgas_fits_committee.txt
and ftp://fits.cv.nrao.edu/fits/traffic/wfc/wfc.dis) request that the
Committee consider this checksum proposal. This could lead to much
discussion (there is a special Email exploder for WFC deliberations),
the members could produce one or more additional implementations,
various refinements to the text or technical details of the proposal
could be suggested and implemented, etc. Eventually the Chair of WFC
will ask the Committee members to communicate by private Email if any
of them object to the proposal or if for some reason they will not be
ready/able to vote on the proposal during a certain specified period
(usually one week). A major reason for asking this question is that
the Chair wants to find out whether anyone might want to vote NO. Of
course, a committee member who has objections should have voiced those
objections during the discussions, and those objections should have
been dealt with by the Chair and the authors of the proposal. An
important goal of the FITS community is that all votes in all FITS
committees should be unanimous if at all possible (so far, there has
never been a NO vote in any of the FITS committees). Finally, when the
WFC Chair judges that the members are all ready, the Chair calls for
the vote by Email, with a deadline.  If the WFC approves the proposal,
the proposal will be forwarded to the IAU FITS Working Group (the
control authority for the FITS standards). The IAU FWG will not
consider the proposal until the other regional committees (Japanese,
European) have also approved it by formal votes (in the case of the
BINTABLE/Blocking/IMAGE proposals, this stage of the process took more
than a year).  The IAU FWG will review the proposal yet again, may
make additional modifications (the regional groups may have approved
slightly different proposals), may require yet more interoperability
testing, etc. The successive revisions to the proposal will be placed
in anonymous-FTP archives and the whole FITS community will be asked
to review them and comment.  Eventually, when the IAU-FWG Chair judges
that consensus has been achieved, the FWG will conduct its own formal
vote on the final proposal. The IAU-FWG requires YES-votes from 3/4 of
the voting membership and no NO-votes for approval on first try, and a
six month delay and a second 3/4 YES if any NO votes were cast (the
intent is to discourage NO votes and to encourage compromise to
achieve total consensus). For the BINTABLE standard, this whole
process, from initial concept through prototype implementations to
final standard, took about seven years. BINTABLE was an exceptional
case -- proposals as simple as the checksum idea should take no more
than four years. Of course, by the time the IAU-FWG completed the
process for BINTABLE, some institutions had more than five years of
production experience with the format, several spacecraft projects and
ground-based telescopes had committed to use it for their data
products, and everyone was firmly convinced that it was a good idea.

Don Wells
Chair, IAU FITS Working Group
--
  Donald C. Wells         Associate Scientist         dwells at nrao.edu
                    http://fits.cv.nrao.edu/~dwells
  National Radio Astronomy Observatory                +1-804-296-0277
  520 Edgemont Road,   Charlottesville, Virginia       22903-2475 USA