[tdwg-content] Occurrences, Organisms, and CollectionObjects: a review

[Steve Baskauf]

Paul J. Morris wrote:
> The definition of collection object has been bothering me, and I'll use
> Steve's comment below as a jumping off point.
>
> On Thu, 8 Sep 2011 06:02:49 -0500
> Steve Baskauf <steve.baskauf at vanderbilt.edu> wrote:
>   
>>  Being derived from an Organism is the minimal 
>> requirement for a collection object.
>>     
Well, my point here wasn't that the collection object must be derived 
from a SINGLE organism.  I don't see any reason why a collection object 
could not be an aggregate derived from several organisms.  In fact, 
there may be more cases where a collection object contains evidence for 
more than one organism than there are cases when it is derived from a 
single organism.  I don't think there is a problem with that.  Take the 
collection object which is an image having the GUID 
http://bioimages.vanderbilt.edu/baskauf/15833 .  That image includes 
visible parts of at least 16 organisms.  At the present moment, I'm 
interested in documenting the big tree in the middle of the picture, but 
that doesn't stop me from creating identifiers for any of Organisms that 
are the five people who are also shown in the image if I had a reason to 
do so.  The existence of any of those people could be documented by the 
CollectionObject which is the image just as easily as the tree.  The 
actual point of my statement was that a CollectionObject that had no 
obvious connection to an Organism (such as an abstract painting in a 
museum) would be outside of the scope of DwC. 
> ...
>
> In many instances in many collections there is not a one to one relationship between a collection object and an organism.   In lot based collections, collection objects are often sets of individual organisms.  In some disciplines, collection objects are often aggregates of many different individuals belonging to multiple different taxa.  Collection objects are often heirarchies of derived objects derived through various preparation techniques (the bulk sample that has been partly picked with macrofossils sorted into lots by higher taxon, with some of these lots sorted and identified down to the species level, with some parts of some specimens mounted on SEM stubs; or the mouse prepared into multiple preparation types).  
>   
As I said, what is the problem with that?  We are not demanding a 
one-to-one relationships between a collection object and an organism.  I 
would say the connection is at least potentially many-to-many.
> A short definition of a collection object might be: "a thing that can be sent on loan from a collection".  
>   
This definition is problematic.  The large oak tree having the GUID 
http://bioimages.vanderbilt.edu/vanderbilt/7-314 is a part of a physical 
collection (the Vanderbilt arboretum).  However, it cannot be sent on 
loan.  The definition as it stands does not limit CollectionObjects to 
physical objects and I don't think is should be because the goal (at 
least I hope it's a goal!) is to allow things other than museum 
specimens to document organisms.  I would say a better definition is 
that a CollectionObject is a resource that has been cataloged and is 
being maintained as part of a collection.  That would include any 
PreservedSpecimens, but would also include LivingSpecimens, Images, 
MachineObservations, etc.  If the history of the name "CollectionObject" 
is an impediment to people's understanding of what it means, then use a 
different name.  But I think then broadening the meaning to include all 
kinds of things that are maintained as persistent evidence is fine as 
long as the meaning of the term is documented clearly (which I think it 
is in John's definition) . 

Steve

-- 
Steven J. Baskauf, Ph.D., Senior Lecturer
Vanderbilt University Dept. of Biological Sciences

postal mail address:
VU Station B 351634
Nashville, TN  37235-1634,  U.S.A.

delivery address:
2125 Stevenson Center
1161 21st Ave., S.
Nashville, TN 37235

office: 2128 Stevenson Center
phone: (615) 343-4582,  fax: (615) 343-6707
http://bioimages.vanderbilt.edu