On 30 Mar 2009, at 16:12, Oliver Ruebenacker wrote:
Hello Bijan, All,
On Mon, Mar 30, 2009 at 7:35 AM, Bijan Parsia
<bpar...@cs.manchester.ac.uk> wrote:
Isn't that the typical way, that ontologies define classes and
properties and users of these ontologies instantiate these classes?
Nope. It's "a" way, but it's hardly typical and the way you talk
about it is
seriously misleading.
Can you name any popular ontology that does not primarily declare
classes and properties?
I don't have to, since I'm not claiming that.
[snip]
So, that's just not a helpful way to think about things in the owl
context.
I myself do use the "TBox=schema; ABox=data" analogy sometimes,
but I fear
that its utility is limited and risk of misinterpretation very high.
It's not an analogy. It's a typical use.
The problem is that "schema" and "data" have strong connotations
which don't hold for OWL ontologies.
Second, there's lots of ways to use ontologies with out having to use
logical constants (i.e., individuals). Alignment of database
schemas comes
to mind. There you might never lift the database data into the
ontology, but
merely use information from the alignment to rewrite queries.
You mean, you rewrite queries never to be run?
No, who said that?
Then, what are you
rewriting them for?
You're rewriting SQL queries, not SPARQL queries.
That's not to say that anyone writes class descriptions intending
them to be
necessarily empty (i.e., unsatisfiable). Just that instance
retrieval is one
task among many.
I wasn't talking about tasks, but of a pattern I found almost all
ontologies I have seen so far to conform to. Instead of philosophizing
about it, why don't you just show me a popular ontology that does not
fit that pattern?
NCI thesaurus.
Cheers,
Bijan.
