I realize that I had missed this email from Steve previously.
I don't understand why Rich says that the creation of this class
eliminates the
need for a class for "evidence". Perhaps he will elaborate when he has better email access.
I guess I'm confused about what the difference between "Evidence" and "Individual" is.
Ultimately, we want an Occurrence to represent the existence of a particular organism at a particular place and time (at least I *think* that's what we want???)
So, if an Event represents a Locality+Time, then an Occurrence serves to represent an Event+Organism.
An Organism is asserted to be a member of a Taxon, as established via an Identification instance. Thus, from Event+Organism, we can derive Event+Taxon (the Taxon inherited via an Organism linked to an Identification linked to a Taxon). Thus, people can get "Taxon at locality & time" through linking a set of instances of these classes (Locality, Event, Occurrence, Organism, Identification, Taxon).
The part I'm a little bit fuzzy on is were "Evidence" fits in to this model. If the function of "Evidence" is to represent proof of the Occurrence (i.e., that the indicated Organism actually was associated with the indicated Event), then I guess I can see the rationale and need for it. I'll need to keep thinking on this one a bit more, but as I write this email, and re-read Steve's earlier post, I'm beginning to get my head around it. But I'd still like to see exactly where it fits in the diagram. Also, does a literature citation of a particular organism at a particular place/time constitute a form of Evidence? Or is that simply captured as an Occurrence, without any tangible evidence (as, I imagine, an Observation would be captured)?
Aloha, Rich