W3C home > Mailing lists > Public > public-semweb-lifesci@w3.org > March 2013

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

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Fri, 15 Mar 2013 17:55:05 -0400
Message-ID: <514398B9.2060207@openlinksw.com>
To: public-semweb-lifesci@w3.org
On 3/15/13 4:40 PM, Jeremy J Carroll wrote:
> I think Jim's solution looks to me like the best realistic one going 
> forward … having somewhat looser variants of owl:sameAs and ask people 
> to be a bit honest with their use of sameAs …
> For Alan's approach, I feel a problem is that what we are doing is 
> making an approximate model of the world, not a completely accurate copy.
> Alan is of course correct that the description and the thing are 
> different, and if we want to be precise we would make that clear, and 
> failing to make this distinction may lead us into trouble; but 
> whenever we say anything about anything, the things we didn't say 
> greatly out-number the things we did say, and making a judgment as to 
> what is important is hard, and people will get it wrong.
> I think most people, most of the time, do not want to be bothered 
> saying, "Well this is my opinion, and your opinion may differ, and 
> believe me if you wish" …. which is what making the careful 
> distinction between the thing and its description amounts to.
> So IMO, Alan is correct, but somehow missing the point.
> Jeremy

Attempting address a variety of issues associated with this thread, via 
links to posts that include live demo links:

1. http://bit.ly/Y6TIfs -- a note demonstrating the use 
owl:InverseFunctional relation semantics, conditionally
2. http://bit.ly/UydU9t -- similar exercise whereby FOAF and vCard are 
3. http://bit.ly/WmKlJ0 -- similar exercise overtly covering symmetry, 
inverseOf (quietly demonstrating transitivity)
4. http://bit.ly/YgLgtk -- looking for ontologies that define a "Likes" 
relation from a Virtuoso instance hosting 55 Billion+ triples.

> On Mar 15, 2013, at 12:56 PM, Alan Ruttenberg 
> <alanruttenberg@gmail.com <mailto:alanruttenberg@gmail.com>> wrote:
>> 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.
>> Best,
>> Alan
>> On Fri, Mar 15, 2013 at 2:55 PM, Umutcan ŞİMŞEK <s.umutcan@gmail.com 
>> <mailto: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 <mailto: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 :-)



Kingsley Idehen	
Founder & CEO
OpenLink Software
Company Web: http://www.openlinksw.com
Personal Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca handle: @kidehen
Google+ Profile: https://plus.google.com/112399767740508618350/about
LinkedIn Profile: http://www.linkedin.com/in/kidehen

Received on Friday, 15 March 2013 21:55:28 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 7 January 2015 14:53:01 UTC