Duane –
I don’t have any suggestions about how one might best
use URL’s to reference ontology elements. However, I do have some
thought about whether one might or might not want to.
I’m not quite sure what you intend to accomplish by
allowing taggers to link their tags to upper ontology elements from any old
ontology. Since the relationships of the upper ontologies to each other
have not yet been well developed, it would only be useful for those who have
chosen to tag by reference to the same ontology. That might be somewhat
useful, but see the caveat below.
If, however, you think this is a way to bring the power of
crowds to actually finding the relations among ontologies (i.e. a tag
referenced to more than one ontology creates a putative identity link), then
this is an interesting new way to go about the ontology mapping task. But
that method has a problem:
Caveat: since upper ontologies
are hard to understand, I suspect few taggers will have the patience to work
though those structures except to find the most common tags like “person”
or “organization”, and in those cases the bare tag would probably have
a common-sense meaning which others would understand without the ontology
reference.
An example of the problem is
the axiom you gave, apparently taken from SUMO. To interpret it, one
needs to read the documentation for the ‘time’ relation. For
perspicuity, I would recommend that any project of that type at least rename
the relations with a verbal form – in this case ‘existedAtTime’.
That can help users at least avoid having to puzzle over their recollection of
the meaning and polarity of the relation. The whole relation means that
an Object exists at every time point within *some* time interval.
I have never been able to figure out under what circumstances this axiom might
be useful in inference, though it makes a sensible philosophical statement
about physical objects.
It would be good to see
crowds adopt a single ontology that is well-structured but easy to understand.
In that case I think the best tactic is to have such an ontology
developed by the taggers themselves for their purpose, with the help of some
willing ontologists. The existing ontologies can be taken as starting
points, but having the taggers use a common ontology would be a lot more
effective.
If you think that there is a clamor
among taggers to use some particular existing ontology, so that that one of
them must be included in the mix that the taggers use, I would be very interested
to know which ones have that distinction. So far the biggest public
tagging corpora I know of reference WordNet.
As for versioning, in the cases I am familiar with,
new elements tend to get added, but the basic structure of the main elements
seldom changes (though the WordNet indexes change). There are occasional
exceptions, one of which happened with the way Cyc handles attributes, a few
years ago. But since the process you describe is so subject
to variation that I think that the variation added by ontology versions will
not be significant, and I wouldn’t worry about versioning – at least
beyond the 1.0 stage.
Pat
Patrick Cassidy
MICRA, Inc.
908-561-3416
cell: 908-565-4053
cassidy@xxxxxxxxx
From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx
[mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Duane
Nickull
Sent: Wednesday, April 22, 2009 6:10 PM
To: [ontolog-forum]
Subject: [ontolog-forum] Namespaces for ontologies
Hey
all:
I am right now placing FOL binary relationships into the associations binding
for labeled relations in a test Registry-Repository. I am doing this
because I got sick of just talking about this and not actually coding and doing
something to solve the problem so the Canadian cowboy instinct to code first and
see where problems arise has taken over.
I have run into a problem that I would appreciate input on. My goal is to bind
something like this:
(=>
(instance ?OBJ Object)
(exists
(?TIME1
?TIME2)
(and
(instance
?TIME1 TimePoint)
(instance
?TIME2 TimePoint)
(before
?TIME1 ?TIME2)
(forall
(?TIME)
(=>
(and
(beforeOrEqual
?TIME1 ?TIME)
(beforeOrEqual
?TIME ?TIME2))
(time
?OBJ ?TIME))))))
..to a registry-repository instance to allow folksonomy tags to reference the
upper level ontology classes the folksonomy tag owners believe they belong to.
Additionally, each instance of a folksonomy tag may have * relationships
to other ontology classes or even other folksonomy tags. The latter
relastionships can be defined in terms of contrained relationship tags like
“synonym, disjoint, etc.”.
I want to represent all upper ontologies however some of them contain subtle
nuances between their terms. Dolce, SUMO and others have defined binary
relationships like transitive, intransitive, reflexive, irreflexive,
symmetrical as well as some partial ontologies. The problem is that there
are no namespace qualifications for these so I want to introduce that into my
work. I was planning on just using the root URL’s for each work
however there are versions possible in some of the work.
I would like this to be in the firm of
<upper_ontology_identifier>+<version_or_instance>+<uuid>
as a classifier followed by the term label such as “transitive”.
I will probably use URI’s for the UUID.
Question:
Has anyone ever come across a similar problem and if so, how did they solve it?
Thoughts and comments welcome too.
Duane