Hi Markus,
Very briefly:
First of all I see an essential difference in character between the
current dwc
idea of Individual(ID) and a MaterialSample, Occurrence, Evidence or
alike:
Yes -- everyone seems to agree that Occurrence, Evidence, and Individual are fundamentally different things (as are Event, Location, Taxon, etc.).
The part that is not so clear to me is where the difference is between what was intended to be represented by dwc:individualID, and what is proposed for materialSample(ID). There seems to be some broad overlap in these two things, with no clear distinction of where one ends and the other begins.
The Individual has no notion of time and space, whereas the others all
have.
I don't think it is true that MaterialSample has a notion of space and time -- any more so than individualID does (or should).
The proposed definition of materialSample is:
"The category of information pertaining to the physical results of a sampling (or subsampling) event. In biological collections, the material sample is typically collected, and either preserved or destructively processed."
There is no class "individual" in DWC; but if there were one, it should have a definition something like this:
"The category of information pertaining to the physical basis of a sampling, subsampling, or observational event. In biological collections, the individual is typically a named group of organisms, a single whole organism, or a part of a whole organism that is collected or otherwise documented in nature, and either preserved, destructively processed, or documented through some form of Evidence (such as images or reported visual observations)."
At least, that's how we have interpreted the generalized intended meaning of what an "individualID" should refer to (i.e., identify). Unfortunately, as has already been pointed out repeatedly in this thread, the term "individual" comes with a lot of baggage, and is not the best term to use (for several reasons). Also, the current definition of dwc:individualID is very thin and too narrowly focused on "resampling" -- which is certainly one of the reasons for having such a class, but also certainly not the only reason.
IndividualID was primarily added to Darwin Core to group occurrence
records
about the same "Individual", e.g. when dealing with bird ringing, whale tracking or tree tagging. It could also provide useful to track herbarium duplicates. The actual Individual class does not hold any direct dwc term
as
they are all dependent on time or locality (think about occurrence
classics
such as life stage, sex, behavior etc). So in this light MaterialSample
and
Individual are very different concepts which we should keep distinct I believe.
I don't agree. Our own interpretation of what an individual class would look like was very-much shaped by the earlier (2010) discussions on this list for what was actually needed by more than a few data providers and consumers. While the addition of "dwc:individualID" may have been done hastily and with a narrow purpose in mind, the broader problem is that the "Occurrence" class is overloaded. I agree with you that the properties that you mention (life stage, sex, behavior, etc.) are properly a function of time and space, and therefore are legitimately associated with a specific Occurrence instance; however, certain other terms associated with dwc:Occurrence (such as catalogNumber, preparations, disposition, otherCatalogNumbers, previousIdentifications, associatedSequences, and taxonomic determinations) are independent of time and space, and are inherently properties of the "individual"/"materialSample" instance.
Put another way, the reasons why an instance of "materialSample" is not equivalent to an instance of "Occurrence", are the same reasons why the notion of "Individual" (sensu me) and "IndivisualOrganism" (sensu DSW) are not equivalent to an instance of "Occurrence".
The motivation for my initial posting to this thread was the recognition that many of the reasons for establishing "materialSample" are the same as the reasons why Steve Baskauf, and I, and a number of others saw a need for "IndividualOrganism" (or whatever it should be called). This is not to say that they necessarily *are* the same thing (materialSample and IndividualOrganism) -- but the overlap is broad enough that it bears some deserves some discussion -- if for no other reason than to inform the discussion on "materialSample" by what has already been discussed for "IndividualOrganism"'; and to clarify the definitions of each to make sure the community (both providers and consumers) understand the differences between them.
Another surprising outcome of an exercise to actually map a large number
of
use cases to darwin core records with real values (using the text
guidelines)
was that we ended up preferring a dynamically typed Occurrence class via the basisOfRecord property and mostly did away with any class terms. This actually draws on Steves proposal to only add a new dwc type term to basisOfRecord instead of creating a new MaterialSample class term. Along with a much richer, hierarchical and probably ontology controlled
definition
of such basisOfRecord terms we felt we can go a long, long way.
This is very similar to our thinking on this as well; except we have found reasonably good congruence between many key properties with the specific basisOfRecord, such that some of them (particularly Evidence and IndividualOrganism) emerge in a way that seem to justify recognition at the Class level. In any case, we need to be careful not to overload "Occurrence" even further. I think that, whatever we do, we should focus on reducing confusion, rather than increasing it.
Aloha, Rich