On Jul 29, 2009, at 12:38 PM, Simon Reinhardt wrote:
Alan Ruttenberg wrote:
On Wed, Jul 29, 2009 at 12:54 PM, Yves
Raimond<yves.raim...@gmail.com> wrote:
and so we didn't got the incentive to
write a better one. Among those examples, you have:
* A score in a musical performance
* A musical instrument in a musical performance
* A piece of text in a reading
* A microphone in a recording
A chair in the room? The door to leave? The program handed out to the
audience? The audience? The light bulb illuminating the room? The
food
that audience ate while watching? The videotape that was being used
to
record the performance? The city in which the performance took place?
I think that's splitting hairs. If the light bulb is important to
you then add it to your data. With RDF it's always pretty much up to
you what you do, right?
Wrong. At least in this sense. RDF doesn't itself constrain what is
said, but RDF just allows the ontologies to be transmitted, and the
whole point of an ontology like this is that it *does* constrain
meanings. Why would I use a concept like event:Factor? Presumably so
that others can (write software which will) understand what I intend
to mean by using it. Its meaning, specified (perhaps loosely, but
specified) by its home ontology, is one I wish to use in conveying my
ideas by this usage. That is what such ontologies are for, it is their
intended purpose. And if no specification is given at all, then there
is no point in using it: I might as well make up my own URI and
declare that it captures my intentions more exactly. And you, reading
the RDF that I publish, will have no greater or lesser idea as to what
it is that I intend to say than if I were to use event:Factor. Which
is a reductio ad absurdum of the whole idea of having ontologies in
the first place.
The ontology user and data publisher is as responsible for data
integration as is the ontology designer.
Bears some responsibility, indeed, but the responsibility of the
ontology user should be to use the ontology's terminology in ways that
conform to the declared intent of the writer of the ontology. In order
to exercise this responsibility, therefore, there must be at least
some explanation of what that intention actually is. I do not ask for
elaborate logical analysis, but surely it is not unreasonable to ask
for something which is not absolutely vacuous. To be told that
event:Factor means a factor of an event is to be told absolutely
nothing. And to be told absolutely nothing in the cited documentation
of an ontology being proposed for universal use is, in my world,
somewhat offensive, even insulting. It amounts to reading a manual
which says "This is so obvious that I cannot be bothered to even take
the time to explain it to you." And this is not a good attitude to
take towards the people who are, in effect, your customers.
And if the data consumers thing you went too far and have too much
noise in your data then you have to fix that.
There is no way to know if data contains noise, when the concepts have
no characterization.
And while the Event ontology doesn't state event:Factor and
geo:SpatialThing to be distinct (maybe they didn't want to make such
statements about other people's terms - with OWL 2 they could do
this for event:factor and event:place now though) I think it's
pretty obvious that you're supposed to use event:place for the city
in which the performance took place (or more exactly for the venue
which is in the city).
Ah, if only such things were obvious. No, it is not obvious that
event:place means the city. or even that one person's place might not
be another person's factor. And BTW, your mention of venue raises an
interesting question: can one event be in several event:places? For
example, if the recording was made in a studio in Los Angeles, would
it be acceptable to have the event:place be USA? Or would that simply
be wrong? The point being, of course, that shouldn't the ontology
specification say **something** about issues like this? Questions like
this matter when one wants to retrieve data based on conditions (find
all the recordings that were made anywhere in the USA before 1997.)
Pat Hayes
Regards,
Simon
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