David,
Thanks for the guts to stroll into the lion's den.
David Baxter wrote:
Hi all,
We at Cycorp have been publishing owl:sameAs links from our OpenCyc
concepts to WordNet synsets, e.g.
<http://sw.opencyc.org/2008/06/10/concept/en/India> owl:sameAs
<http://www.w3.org/2006/03/wn/wn20/instances/synset-India-noun-1>
We've done so with the idea that the WordNet synset represents the same
concept as the OpenCyc term (i.e. the South Asian country in this case),
and contains further relevant information that complements what is
available in OpenCyc, e.g.
"is a member of OPEC" (OK, this one's of dubious value, but it might be
useful if it were true)
"is a member of the British Commonwealth"
"is a part of Asia"
However, WordNet also contains assertions about the "India" synset that
seem strange to assert about the country, e.g.
"is an instance of NounSynset"
"contains WordSense 'Republic of India 1'"
We'd like to know what the general feeling in the LOD community is about
these links. Is there any precedent or consensus about the best way to
link from ontologies such as OpenCyc's to WordNet? Is anyone finding
these links useful and/or harmful?
Thanks for any input.
I've rolled back to your starting message since intervening
comments have unfortunately snipped out the essence of your
question about owl:sameAs. Let me also again add this link from
over the weekend that I think is also germane:
http://i9606.blogspot.com/2009/02/semantic-dissonance-in-uniprot.html
As I understand the current OWL, "an owl:sameAs statement
indicates that two URI references actually refer to the same
thing: the individuals have the same 'identity.'" [1]. In logical
terms, I understand this to represent complete and total
identity, equivalent to the '=' relationship, or something pretty
doggone close to it. I also understand this property to perhaps
have the strongest entailment of any OWL property.
The inference from your use case and the similar issue with Ben's
uniprot example are all too typical of sameAs problems once
disparate datasets actually get pulled together.
I appreciate the rdf:seeAlso suggestion; it is the most common
fallback. But the issue with that one, which is why you went to
sameAs in the first place, is that seeAlso is way too weak to
convey the nature of the relationship. Sure, we could do a
subPropertyOf but we could at best capture only the very weak
semantics that seeAlso presently provides; we could not
strengthen it.
I think the real issue is that we don't have a readily available
(or at least accepted) predicate. I would suggest, though, that
the issue at hand is very much captured by the concept of
"relative identity":
http://plato.stanford.edu/entries/identity-relative/
esp. Section 3 (though there are some wonderful paradoxes
throughout).
What I like about 'relative identity' is that we can still infer
and reason over the relationship (but *how* and weak or strong
still is up for grabs).
I think the considerable experience of Cycorp in such matters
could be invaluable in severing this Gordian knot. Care to
stroll deeper into the den?
A hasRelativeIdentity B ??
Thanks, Mike
[1] http://www.w3.org/TR/owl-ref/
