Use of DAML+OIL/SkiCal and iCalendar in DAML+OIL

[Bernard Vatant]

*Tony Linde
> In the scientific domain, such as with astronomical VOs, it is
> different. While we still have the issue of determining the right way to
> map concepts as classes, whether using a data modelling or ontological
> approach, there is an additional problem with creating the instances.
> Three people may analyse the same data for a given point in the sky: one
> will say the object is a brown dwarf, one will say it is a 'green fairy'
> and the third may say that the readings are simply errors in the
> instrument. All three 'statements' must be possible about the same set
> of data points.

This is fairly close to the situation exposed at
http://archives.us-vo.org/semantics/0033.html

A Topic Map view of such a situation would be as following:

- The observation data set itself is a specific resource (image, spectrum, whatever ...)
- It is identified by some locator URI, and attached some relevant metadata (observation
source, date, quality, format ...).
In Topic Maps terminology, this resource is an "addressable subject", stored somewhere in
the network, and retrievable through its locator. It is represented by a specific topic,
say "Obs-ABCD-1234".
- This topic can be classified through various hierarchies (observation type, bandwidth,
instrument, protocol ...)
- This topic is related to other topics like Instrument X, Team Z, Observatory K, Project
W, through specific associations.

All the above, expressed by a specific network of associations involving topic
"Obs-ABCD-1234", is completely independent of and distinct from any out there object - if
any - this observation is supposed to "represent", "show" or "be Image Of".
All the above looks like regular "enterprise content" and is likely to be managed as such,
with not too many ontological issues: objects and types in it are not too much
controversial in identity, they are like any other down-to-earth business objects.

Now you got your two interpretations of "Obs-ABCD-1234" as so many distinct topics.

"BD_0524-0867"     (instanceOf "Brown Dwarf")
"GF_4567"            (instanceOf "Green Fairy")

The observation interpretation can now expressed as specific associations, in different
scopes,
like:

(1) Observation-Interpretation [observation: Obs-ABCD-1234, object: Brown Dwarf 0524-0867]

If you consider there is no out-there object, but just instrumental artifact, just
classify Obs-ABCD-1234 as junk :)

> Or perhaps what we're looking for is a way in which the set of data
> points is only ever represented by these 'statements'. The 'object' is
> never instantiated as an instance of one or other classes - bit like
> quantum superposition except that resolution is never absolute :)

The above way to do is somehow avoiding the quantum superposition effect, by making the
interpretation different in different scopes. "BD_0524-0867" is a brown dwarf by
definition. I can always say there exists an instance of the class Brown Dwarf called
BD_0524-0867 - even with the status of unproven assertion, and try to gather consistent
information about it. That there "is" an object out there "belonging" "really" to the
brown dwarf class is another (metaphysic) issue.

All the problem is to know if the assertion expressed by (1) is consistent with:
-- the current definition of brown dwarf class
-- consistent interpretation of Obs-ABCD-1234
-- previous data/information/knowledge, if any, concerning BD_0524-0867

The superposition effect happens only if you want to consider different interpretations as
likely. But it's a very good analogy. And BTW Nikita Ogievetsky, (former neutrino
physicist and now topic maps guru) has developed the notion of "quantum topic maps".
A fascinating aspect of it is that, like a quantum object, any subject is changed by (not
to say made of) the assertions you make on it (interpreted as interactions), and is not a
static out-there realistic "thing". I forward this to Nikita, hoping to see him jump in
the debate with fascinating insights :))

See http://www.cogx.com/kt2002/

Bernard

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Bernard Vatant
Consultant - Mondeca
www.mondeca.com
Chair - OASIS TM PubSubj Technical Committee
www.oasis-open.org/committees/tm-pubsubj/
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