characters/states and measurements and other hoary problems
Stuart G. Poss
Stuart.Poss at USM.EDU
Mon Aug 7 18:49:51 CEST 2000
Kevin Thiele wrote:
An item in the DDS is like an old OTU - it may be anything from a specimen
> to a species to a Kingdom.
> The possibility of specimens being items comes from the ability to nest
> e.g. Treatment A comprises measurements of a series of specimens of
> Imaginaria magica for some characters (e.g. hypopode length). Treatment B
> comprises as its items species of Imaginaria. Some characters (e.g. CAM
> metabolism) are scored directly in B while others (e.g. the range of
> hypopode lengths) are collated from A.
> Data for the character hypopode length in B would then be attributed to
> treatment A, where each data element is attributed to measurements taken by
> me on a specimen. Redetermination of a specimen followed by rebuilding of
> the treatment tree would allow the redetermination to be incorporated all
> the way up.
> Would this work, and does it address your query?
This seem plausible to me.
The only complication that comes to mind is the situation where one might have
two inconsistent identifications of particular specimens. How would the
redetermination rule work with respect to A if one has a Treatment C, say for
hypopode width, for which the ID for (some?) of the same specimens in A is
inconsistent with that used in treatement A?
If the inconsistency is based on soley a difference of combination (perhaps old
synonym incorrectly used) one could make the redetermination automatically (using
the nomenclaturally appropriate combination). Otherwise, I'm not sure what flags
get raised since it would depend on the nature of the inconsistency. Perhaps
just throw the data back to the user with an error message and let them make a
decision might be the appropriate response? This could certainly aid in
identifying mistaken identifications, but in any event there probably needs to be
some kind of default logic once inconsistency in the data is located. It will be
difficult to eliminate entirely.
> >One file will comprise one treatment, the basic unit of which is one or more
> >characters describing one or more taxa or individuals.
> Surely the data level to which a character is attributed is determined by
> the context of the treatment:
I would agree. I think its a question of to what extent we want the system to be
able to make (part of) the inference for us so that we can be aware of the
"universe" of features out there for which there are relevant data. When the
data are initially recorded they are most likely defined within a much narrower
context. I'm still struggling with how we can determine the extent to which the
rules might be constructed to determine (identify/establish) context.
> Another collation rule may convert low-order numeric data into a
> higher-order multistate:
Could be lots of options here.
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