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Re: owl:sameAs - Is it used in a right way?

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Date: Fri, 15 Mar 2013 15:56:40 -0400
Message-ID: <CAFKQJ8mxUpge1iv5xf00b1yaSY6ie=ERiD43SKExWSEXD9TS7w@mail.gmail.com>
To: Umutcan ŞİMŞEK <s.umutcan@gmail.com>
Cc: Jeremy J Carroll <jjc@syapse.com>, Kingsley Idehen <kidehen@openlinksw.com>, public-semweb-lifesci@w3.org
There's another perspective, which is to to distinguish descriptions of
things from the things themselves. This works if you can agree on identity
of the thing but not necessarily on the way to describe it. As an example,
consider the class of cars manufactured by Nissan (call it Cn). If you can
agree on a URI for that class, you can each write descriptions that have
foaf:primaryTopic Cn.

Depending on how careful you want to be, you can then use one or two
graphs. If you have your predicate relate descriptions then you can use a
single graph. For example  instead of having a predicate hasNumberOfDoors
that relates cars to a count of doors you can
have  describedHasNumberOfDoors that relates a description of a car to a
number with the interpretation that the author of the description asserts
that the car has 4 doors.

Or, if you want to make assertions about the car, then use two graphs. Each
can make statements of the sort [isPrimaryTopicOf <description>]
hasNumberOfDoors 4. Since we are talking now about the cars, there could be
different perspectives, so to control that you put each author's assertions
in a different graph.

I think this is a better strategy than using sameAs. There are a bunch of
problems with sameAs, not least of which is that often the assertions are
incorrect - they mean something different, Jim's post gives a strategy to
relate them without using sameAs, but I'd assert that general ways of
relating descriptions takes more than a couple of relations, and should be
an orthogonal problem. With the primaryTopic method I suggest the
relationship that matters for your application - that the descriptions are
pointing to the same thing, is explicit, and doesn't need new predicates,
though it does require some level of coordination.


On Fri, Mar 15, 2013 at 2:55 PM, Umutcan ŞİMŞEK <s.umutcan@gmail.com> wrote:

> That made it clear, thanks again. I'm sure it will be helpful for other
> developers either  in the future.
> Umutcan
> On 15-03-2013 20:29, Jeremy J Carroll wrote:
>> I did not find this a rookie question at all.
>> This seems to get to the heart of some of the real difficult issues in
>> Semantic Web.
>> My perspective is different from yours, and a resource description that I
>> author is a description of the resource from my perspective; a resource
>> description that you author is a description from your perspective.
>> If I have some detailed application that depends in some subtle way on my
>> description, I may want to ignore your version; on the other hand, a third
>> party might want to use both of our points of view.
>> One way of tacking this problem is to have three graphs for this case:
>> Gj, Gu, G=
>> Gj contains triples describing my point of view
>> Gu contains triples describing your point of view
>> G= contains the owl:sameAs triples
>> Then, in some application contexts, we use Gj, sometimes Gu, and
>> sometimes all three.
>> Jeremy
>> On Mar 15, 2013, at 11:02 AM, Umutcan ŞİMŞEK <s.umutcan@gmail.com> wrote:
>>  Thanks for the quick answer : )
>>> So this issue is that subjective for contexts which allows to use
>>> owl:sameAs to link resources  if they are not semantically even a little
>>> bit related in real world?
>>> Sorry if I'm asking too basic questions. I'm still a rookie at this :D
>>> Umutcan
>>> On 15-03-2013 19:38, Kingsley Idehen wrote:
>>>> On 3/15/13 1:05 PM, Umutcan ŞİMŞEK wrote:
>>>>> My question is, does LODD use owl:sameAs properly? For instance, are
>>>>> those two resources, dbpedia:Metamizole and drugbank:DB04817 (code for
>>>>> Metamizole), really identical? Or am I getting the word "property" in the
>>>>> paper wrong?
>>>> The question is always about: do those URIs denote the same thing? Put
>>>> differently, do the two URIs have a common referent?
>>>> ## Turtle ##
>>>> <#i> owl:sameAs <#you>.
>>>> ## End ##
>>>> That's a relation in the form of a 3-tuple based statement that carries
>>>> entailment consequences for a reasoner that understand the relation
>>>> semantics. Through some "context lenses" the statement above could be
>>>> accurate, in others totally inaccurate.
>>>> Conclusion, beauty lies eternally in the eyes of the beholder :-)
Received on Friday, 15 March 2013 19:57:37 UTC

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