SDD standard - purpose

Kevin Thiele kevin.thiele at PI.CSIRO.AU
Thu Jul 20 09:17:32 CEST 2000

Bob Allkin,

Gregor Hagedorn's original posting to the list explains the brief we
received from TDWG. That would be a good starting point - you can get it
(and all previous list correspondence) downloaded by sending the
appropriate message to the server {can anyone tell Bob what that message is?}

This is my take on your questions.

>- who will use this,

Potentially anyone who needs to capture and manage descriptive data, but
this will have to wait on development of appropriate tools. Initially, and
in a more limited scope, it will serve as an interchange format between
existing programs e.g. Lucid, DELTA, XID etc (assuming the developers of
those programs come to the party and write I/O functions.

>- to store what types of information

I think initially we need to be flexible enough to be able to store any
type of morphological or anatomical data. Some chemical descriptive data
could fit in here as well, at least simple "chemical A: present/absent"
statements. I suppose the main thing we seem to be leaving out for the time
being is genome, sequence and protein data - too specialised for our
present purpose?

>- for what kinds of description (for identification as with DELTA) for
>cladistics, for publishing to other audiences

Initially, I think we should aim at descriptions and interactive ID. This
is a problematical area, that I think should be explored more. The idea of
massaging one data file into two or more different products (e.g.
natural-language and keys) is very attractive, but surprisingly
problematical, since the structure of data needed for the two purposes is
often subtly different. Of course, doing just this is the basis of the
DELTA system, but we may need to do it in a more sophisticated way.

As for cladistics, this is more problematical. In the early days of the
list there was much enthusiasm about our standard subsuming NEXUS. I think
I'm right in thinking that the NEXUS people thought this was a bit of a
joke - NEXUS is widely used, is widely supported and seems to be highly
successful, while ours doesn't even exist yet! The problems inherent in the
multiple-product model become even more alarming when you try to maintain
one data file for both description/identification and phylogenetic
analysis. My personal view is that we should leave cladistics out of the
scope at least for the time being. Anyone else out there want to comment on

>- to do what (for exchanging data between different databases, as a public
>format upon which independent applications will run).

Initially, as an interchange format for existing applications, but if it
works, hopefully a new generation of applications will flow.

>I'd appreciate it if someone could point me at a summary of your previous
>deliberations on this.

Other contributors - is this a fair summary?

Cheers - k

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