dichotomy

[jkirkbri at ASRR.ARSUSDA.GOV]

On Wed, 22 Mar 1995, Renaud Fortuner wrote:

> Your example of how the
> red-white-blue flower character is treated in Delta is exactly what I had in
> mind when I said "rigidity" or lack of flexibility. If I understand correctly,
> you have to code, separately and beforehand, all possible states or
> combination of states, and you have to decide, again beforehand, if they are
> going to be used for identification or for natural language (NL) description.
> In my system, you would define the character as : structure = flower,
> descriptor = color, states = red, white, blue, pink. Then species X (all pink)
> would be coded pink (100%), and species Y would be coded white (75%), red
> (25%). It's a WYSIWYWD system: what you see is what you write down! If the
> unknown has spotted flower, the user just adds "spotted" to the list of
> states. The point is that all the states are entered separately, as they
> appear in a NL description or as the user sees them in the specimens, and that
> each type of metadata (here, the percentages) are in a field of their own,
> available for any algorithm that needs them.

I find his argument unconvincing.  There is little difference in the
following two structures, his and DELTA format:
    structure = flower
       descriptor = color
          states = red, white, blue, pink
    #1. flower <color>/
        1. red/
        2. white/
        3. blue/
        4. pink/
Exactly the same structural and character state information is supplied
in both systems; only the syntax of presentation is different.  Fortuner
wrote, "If I understand correctly, you have to code, separately and
beforehand, all possible states or combination of states, and you have to
decide, again beforehand, if they are going to be used for identification
or for natural language (NL) description."  His system has to have the
same prior information as the DELTA format, not one wit less.  If a species
turns out to have unknown, at the time, populations with purple flowers,
then his system and the DELTA format BOTH have to be modified to admit
the newly discovered condition.

The advantage of his system is that it stores metadata, i.e., the
frequency of occurence of character states for each taxon.  For the
majortity of systematic work, I am very skeptical about that type of data.
First taxonomists rarely have, what I consider, accurate frequency data
for all the taxa in a systemtic study.  Secondly, real-life users
99.9% of the time are using an (1) organism for the identification, if
you are lucky, or just a piece of an organism; they lack frequency data
practically all of the time.  Rarely, very rarely, in
real life does a geneticist or ecologist come in with trustworthy
frequency data.  Also, most real users want AN answer, not a
probability.  As you can see from my address, I work with agricultural
scientists, and they get very upset when I "hem and haw" rather than
giving them a name with confidence.

Are systematic studies carried our for our own self gratification, or to
help real people?  Much of the discussion in the last few days has been
very interesting, but it had a very self centered component.  In my
opinion systematic products should help normal, average people to survive
and have better lives.

Joseph H. Kirkbride, Jr.
USDA, Agricultural Research Service
Systematic Botany and Mycology Laboratory
Room 304, Building 011A, BARC-West
Beltsville, Maryland 20705-2350 USA
Voice telephone: 301-504-9447
FAX: 301-504-5810
Internet: jkirkbri at asrr.arsusda.gov