Mapping Lucid Characters to Prometheus
G.Hagedorn at BBA.DE
Thu Mar 18 13:12:17 CET 2004
> The approach that we are proposing is that the descriptions are
> collected as atomic statements, and more traditional 'characters' can
> be discovered by analysis of this data (many characters are apparently
> a collection of atomic scores/states)
> Our taxonomists find this quite a departure from how they compose and
> record their characters at the moment ( they recognize/discover and
> define a set of characters by looking at the variation that exists in
> their specimen, then create a scoring sheet/proforma that allows them
> to pick one of these alternative characters) - our system might be
> tweaked to allow them to work in a more character oriented manner if
> they precompose sets of statements as part of the proforma
> specification, and then score these alternates as present or absent.
I believe when you say "character" in the above you mean what in
DELTA and SDD is considered a character "state"; is that correct? Do
you consider the states to be completely unrelated, i.e. green and
red and hairy and present are all on the same level? Or is this the
collection of state the property or type? This is something I don't
In many aspects, SDD and DELTA treat states are potentially
independent, i.e. characters have semantics, but are otherwise sets
of states. The important deviation is the coding status itself, which
always applies to the entire character.
Can you say in your model that a property is inapplicable or unknown?
> a major advantage of our system can be seen from some of your simple
> characters - eg growth habit: you have split this into two
> alternatives 1. Epiphytic or lithophytic habit vs 2. (not epiphytic
> or lithophytic) whilst this might make sense for a key, and is a
> DELTA-like representation, we would argue that if the ACTUAL growth
> habit was scored for each specimen as epiphytic, lithophytic,
> terrestrial, aquatic ( or concatenations of these ) far more accurate
> information would be recorded. For example, this would allow the same
> specimen description to be divided into other character sets if
> desired ( someone else may think that a key would work better if the
> alternates were soildwelling or lithophytic vs epiphytic, another
> person might want the alternates separately....if the description data
> had been recorded in the orginal two-alternate-character division,
> this data reuse would not be possible.
I think potentially the point your are making is very important, i.e.
that for some (not all) "state sets" there may be different
partitionings motivated by different goals. One potentially can split
color into metallic colors, bright colors, earthen/brownish colors.
However, I think the example above is not well choosen (I assume you
refer to Kevin's General habit and Epiphytic or lithophytic habit. It
is quite possible to have combinations of these. Epiphytic plants may
be climber, herb, or grass- or sedge-like plant.
> I hope this shows some of the salient features of our model...and how
> we think it would beneft working taxonomists.
(The rest of the email is unfortunately not readable to me, you seem
to use some Microsoft Office or Outlook specific feature to construct
> LUCID CHARACTERS<?xml:namespace prefix = o ns =
> "urn:schemas-microsoft-com:office:office" />
> Salt tolerance
> · plants tolerating high salt levels (halophytes)
> · plants not salt tolerant
> Entire Plant
> Ecological Adaptations
> (there are a list of alternate states that could be scored, or
> NOT-halophytic is allowed)
> General habit
and so on
Gregor Hagedorn (G.Hagedorn at bba.de)
Institute for Plant Virology, Microbiology, and Biosafety
Federal Research Center for Agriculture and Forestry (BBA)
Koenigin-Luise-Str. 19 Tel: +49-30-8304-2220
14195 Berlin, Germany Fax: +49-30-8304-2203
Often wrong but never in doubt!
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