Just to further elaborate on the example:
If we assert:
dwc:HumanObservation
rdfs:subClassOf dwc:Event.
and then someone stated:
<birdObservation1>
rdf:type dwc:HumanObservation.
I think that would entail:
<birdObservation1>
rdf:type dwc:Event.
because of the semantics of rdfs:subClassOf
On the other hand, if we assert something like
dwc:HumanObservation
skos:narrower dwc:Event.
that would NOT entail
<birdObservation1>
rdf:type dwc:Event.
but instead would entail different stuff like:
dwc:Event skos:broader
dwc:HumanObservation.
dwc:HumanObservation skos:narrowerTransitive dwc:Event.
etc.
None of these entailments are intrinsically good or bad. But if we
make assertions like
dwc:HumanObservation
rdfs:subClassOf dwc:Event.
or
dwc:HumanObservation
skos:narrower dwc:Event.
we must be aware that a machine could reason the entailed
relationships, and should only make those assertions if we want a
machine to be able to do those kinds of reasoning. In other words, we
should only make assertions with semantic implications to accomplish
some purpose related to machine reasoning, and not just because it
seems like it might be a good idea. If our purpose is just to make
things more clear to a human, then providing a better human-readable
definition would be a better way to accomplish that.
Steve
Richard Pyle wrote:
dwc:HumanObservation rdfs:subClassOf dwc:[Occurrence]
But what would I gain by doing that? What would it prevent me from doing?
I'm not technically savvy enough to answer that question from an
implementation perspective; but from a DwC comprehension perspective, it
moves us a step closer to mutual understanding of how to transform DwC
content into a functional data model. We all kinda/sorta know that already,
but as evidenced by the different perspectives of "HumanObservation as a
subclass of Event" vs. "HumanObservation as a subclass of Occurrence" just
now revealed & expressed, it probably wouldn't hurt to be more explicit
about these sorts of things in DwC documentation.
--
Steven J. Baskauf, Ph.D., Senior Lecturer
Vanderbilt University Dept. of Biological Sciences
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