As shown in this RDF
All the occurrences of this species will have this "type"
All the individuals of this species will have this "type"
Which then makes it easy to query for all occurrence or all individuals of this species concept.
The exact predicate is different but when you tie a subject to and object you are essentially making the subject a "type" of the object.
Which is why you can see the occurrences for that species in the triplestore, when you ask it to describe that type.
- Pete
On Tue, Oct 26, 2010 at 9:46 PM, Hilmar Lapp
<hlapp@nescent.org> wrote:
On Oct 25, 2010, at 4:37 AM, Cam Webb wrote:
> But then what exactly are the Occurrences themselves? From Richard
> Pyle:
>
> ``So, an Occurrence is the intersection of an Individual and an
> Event.
> An Event is a Location+Time[+other metadata]. Each Event may have
> multiple Occurrences (i.e., one for each distinct Individual at
> the same
> Location+Time). Also, an Individual may have multiple Occurrences
> (one
> for each Event at which the same Individual was documented).''
>
> So the Occurrence is the Individual _itself_ bounded by space and
> time,
While for the purposes of exchanging occurrence data in a commonly
agreed upon markup, i.e., Darwin Core, this may be perfectly
acceptable, I think there are some serious issues in the above when we
try to tighten up the semantics so that machines could do something
with them, or so they can seamlessly integrate into the semantic web.
First there is an internal inconsistency: on the one hand occurrences
*are* individuals (albeit only a subset - though see below), and on
the other hand individuals *have* occurrences.
Second, occurrence is said to be the intersection of an individual and
an event, or an individual and space and time. In the semantic web,
OWL models deal with sets of individuals. I would argue that the
intersection set of an individual organism (or a set of individual
organisms) and an event (or a set of events) is empty, because there
are no events that are also individual organisms, and vice versa.
Alternatively, and using "Individuals" as short hand for "instances of
an organism" we could say that an Occurrence is the intersection of
all Individuals belonging to a specific taxon, all Individuals at a
specific location, and all Individuals existing at a specific time.
Then an instance of an Occurrence would be an Individual in that
intersection, and taxon, location, and time would be (among) its
properties.
Just some thoughts.
-hilmar
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: Hilmar Lapp -:- Durham, NC -:- informatics.nescent.org :
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Pete DeVries
Department of Entomology
University of Wisconsin - Madison
445 Russell Laboratories
1630 Linden Drive
Madison, WI 53706
TaxonConcept Knowledge Base /
GeoSpecies Knowledge BaseAbout the GeoSpecies Knowledge Base
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