Thanks, John. I agree that there will be little value in
trying to define and name distinct units of space and time, but there may be
value in defining units along the taxonomic axis. However, we should first come
to a community consensus on what the maximum scope of each axis
is.
My sense is that the maximum scope of space is "Earth" (at
least until we begin documenting populations of extraterrestrial
life).
My sense is that the maximum scope of time is effectively
"any window of time during the past 4 billion years or
so".
But I don't have a clear sense for what the maximum
scope of "one or more organisms" ought to be. I'm content with
extending it to "populations" as a unit of "organisms", because I see a smooth
transition from two individual organisms all the way up to a
population of organisms. But should we accept taxonConcept (which can
be thought of as an implied set of populations) as an extension of
"organisms"? If so, then "Animalia Occurred on Earth sometime during the
past 2 billion years" is a legitimate Occurrence record (pretty damn
useless...but still legitimate).
I think it matters, and is relevant to this exchange -- both
because of Steve's point about more clearly defining what an "Occurrence" can
be, and because we still don't have a good idea of how and where to score
"nativeness" (for which there is clearly an expressed need).
I agree that fitness-for-use should be determined from the
content of the records, but coming back to Donald's (and others') point about
filtering "non-native" records, there needs to be a way to include this
information in the content of the records in order to determine
fitness-for-use. I believe that a controlled vocabulary for
establishmentMeans will probably be all we have to do to satisy 95% of
the user need. But before we can nail down what that controlled vocabulary
would encompass, I think we need to come to some sort of consensus on the issues
that Steve has articulated.
Aloha,
Rich
Occurrence is admittedly a problematic term. Its current definition
is vague following in the grand tradition of Dublin Core term definitions.
Rich's interpretation echoes what Steve wrote and comes closest in my mind to
what an occurrence really is meant to be, namely "evidence of one or more
organisms occurring at a place and time." This leaves open all of the vast
continuum of scales - geographic, temporal, and taxonomic - at which
occurrences can be described. I'm not sure exactly what is solved by trying to
make named distinctions between different scales or levels of detail (on any
of the three axes) of Occurrence. The core of the issue really boils down to
fitness-for-use of records and a potential user's capacity to accurately
determine that. These should be characteristics that can be determined from
the content of the records.