[CF-metadata] CF Conventions 1.2

From: Jonathan Gregory <j.m.gregory>
Date: Tue, 6 May 2008 09:05:45 +0100

Dear Ethan

I think that the current rules are a good compromise between the needs of
people who write and analyse data, and the needs of developers of analysis
and other software. The former group of people would like CF to be modified
fairly rapidly, when they are about to start producing data from a project,
and they want that data to have proper metadata. As you will have seen from
previous discussions, our discussions are too slow as it is sometimes. Hence
we decided the rules so that changes could be made, but marked as provisional.

For provisional changes to become permanent depends on at least two
applications supporting them. That requires some development effort to be
invested. CF doesn't have staff resources of its own to commit to it. I think
the most likely applications to make changes first are the cf-checker and
libcf. It will be interesting to see how long it takes for the changes so far
agreed to be implemented in these or other applications.

I fear that if we followed this approach:

> 2) Don't add changes to the upcoming version of the specification
> document "until at least two applications have successfully interpreted
> the test data".

development of CF would effectively be halted altogether. It would be
impossible for writers of data to agree changes to the CF standard on a
short enough timescale. Consequently they would bypass CF, and write and
analyse data with their own metadata conventions, and the usefulness of CF
in providing a common standard would be undermined.

Applications don't have to keep entirely up to date, do they? I think the
value of the Conventions attribute should be that it is easy to be clear
about what conventions are being implemented in data and metadata.

I agree about the test data. We should construct a file which contains
some test data for the changes of CF 1.2. (The changes of CF 1.1 did not
introduce any new attribute.) We'll need a place to deposit such files.
As moderator of that ticket, I'll discuss it with Phil and Velimir.

Best wishes

Jonathan
Received on Tue May 06 2008 - 02:05:45 BST