[tdwg-content] Background for the Individual class proposal. 3. Should an Individual also be a Collecting Unit?

[Richard Pyle]

Hi Steve,

I really need to read your other messages before I can commpent in full, but
I did want to respond to some of your recent comments, below.

> What if the specimen is from a tree?  I collect flowers in May and return
to 
> collect fruit in September.  I have a hard time making those two 
> Occurrences be one.  

Why would the two occurrences have to be one?  You have an Individual
instance for the tree, and a two more Individual instance for the collected
subsample.  The Individual instance corresponding to the tree could have its
own related Occurrences (e.g., if you took a photo of the tree); and the two
collected specimens would each have their respective collecting event
represented as an Occurrence.  The latter two occurrences can trace back to
the Individual Occurrence by virtue of the fact that both of the collected
Individuals are semantically linked to the "parent" Individual (i.e., the
whole tree).  Isn't that the sort of "reasoning" that RDF is supposed to be
able to allow?  That is:

Tree exists as LivingSpecimen Individual whole tree

Flowers exist as PreservedSpecimen Individual that is part of a tree

Fruit exist as PreservedSpecimen Individual that is part of a tree

The first can have as many Occurrence linked to it as needed (images,
measurements, etc. all taken on different dates).

The latter two likely have one Occurrence each (the collecting Event for
each).

The latter two Individuals are linked as "derivedFrom" or "partOf" or
whatever back to the whole Tree Individual, so that the presence of the
whole tree can be inferred by the Occurrence records for the two parts
(specimens).

> According to the definition on the table for a vote, an 
> Individual is to permit resampling over time.  

Absolutely!  No argument there!  You can go back to the WholeTree Individual
and generate a zillion Occurrence reocrds if you want.  Not a problem.

> You are denormalizing a more general model.  We both confessed to this sin
in an earlier series of emails.  

I don't understand what you mean by that.

> If you don't want to read the first post in the series, 
> just click on the links on order and look at what happens 
> to the diagram.  I want (no NEED) the fully normalized 
> model for what I do and so do others.  

And so do I.

> You may not need it, 

No, I do.

> If I'm the only person who ever needs to resample anything 

You are not.  Nothing in my proposal prevents resampling of an Individual.
In fact, nothing in my proposal prevents *anything* you want to do, as far
as I can tell.  But your proposal prevents me from representing parts of an
whole organism as Individuals unto themselves, which is especially
encumbering when I know that I have many, many, many parts of whole
organisms for which other parst of the same whole organism exist, but I lack
the knowledge to build those links.

> I would just prefer it to be a "well known" Darwin Core term, 
> not an ad hoc one that I made up.  

I would too!  But in the same way that DwC started focused on
DeadSpecimensInMuseums only, and was later expanded to a more general
accomodation of occurrence records for both dead and live things; your
proposal for "Individual" may have started out to fulfill a very specific
need, and I am advocating a slightly broader interpretation that still meets
your specific needs completely, but also accomodates a borader scope of
needs (without denormalizing anything).

Maybe we need a new term like "BiologicalObject" that should be the more
general class, of which "Individual" as a more narroly-defined subclass?

> If it was important enough 
> to put individualID into the Darwin Core standard to 
> facilitate resampling, then why is it suddenly not 
> very important to make that term usable in RDF?

I can't speak to how it would be used in RDF (I am Bob's "BETA"); but I can
see how the same definition of "Individual" can accommodate both sets of
needs rather elegantly.
	
More after I digest your other two messages.

Rich