Last email from me for tonight, I promise.
Overall I like the direction of Denis's proposed definition, but I have a comment and a question.
Comment - I propose to explicitly expand the definition of an obervation to include both organisms and ecological communities (such as vegetation).
Here's a slight change that might work: "An observation is the characterization of the occurrence of an organism (or a community of organisms) through a collection event with a defined protocol and spatiotemporal location. Individual observations are non-independant entities that can be linked to each other through their common characteristics."
The main difference I see is that in the case of ecological communities, you are not only monitoring occurrence (presence/absence), but also changes in the other characteristics of your community.
I think providing a separate definition for Monitoring would also be useful. Monitoring and observational data are 2 different things, although they are obviously intertwined (and sometimes confused). In the case of population monitoring, you are interested in changes of abundance of a population over space and time (and you typically use observation events as sample points to infer larger population changes). In the case of community monitoring, you are usually more interested in changes in the ecolological characteristics of a particular area (and you also use observation events to do that).
And a question - does the "defined protocol" need to be a published document, or can the protocol be more informal? I think that the observer should provide some minimal documentation of how they made that particular spatiotemporal observation, but I'd imagine there's quite a bit of high quality observation in existence that was collected opportunistically and not necessarily using a published protocol.
No, defined protocol didn't imply a scientifically rigorous one or a published one. "Casual data collection" could be a defined protocol. I couldn't think of a better term.
Denis