- From: Alan Ruttenberg <alanruttenberg@gmail.com>
- Date: Wed, 16 Mar 2011 13:30:05 -0400
- To: Pat Hayes <phayes@ihmc.us>
- Cc: Ivan Shmakov <oneingray@gmail.com>, Ivan Shmakov <ivan@main.uusia.org>, "semantic-web@w3.org" <semantic-web@w3.org>
Are graph serializations assumed closed world? In other words, do graph names act the same way other semantic web names do? -Alan On Mar 16, 2011, at 12:34 PM, Pat Hayes <phayes@ihmc.us> wrote: > > On Mar 14, 2011, at 11:56 AM, Ivan Shmakov wrote: > >> I guess I'm close to become an annoyance, but I'm going to ask >> yet another blank node question anyway. >> >> Suppose that I have the following graph: >> >> :joe :has [ a :dog ] >> >> And suppose that I also have the following one as well: >> >> :joe :has [ a :dog ] >> >> From the previous discussion I've learned that there're >> different opinions on whether to consider these graphs, which >> share exactly the same representation, same or different. > > The *graphs* may be different, but what they *say* is the same. Each one simply repeats the content of the other one. So you learn nothing new by having both of them rather than one. > > However, that said, according to the current RDF specs, they are also in fact (perhaps two different serializations of) the same graph. Not that this really matters. > >> In >> particular, there's a position that these graphs are different, >> unless they're named the same. (Somehow, I feel that graph >> naming should be considered tangential to the knowledge it >> represents, but I've noted to myself that there's a different >> opinion.) >> >> But my question is itself tangential to the equivalence of these >> graphs. Instead, I wonder, if I've assimilated this above >> representation into an RDF store, and going to assimilate its >> exact twin again, does this later assimilation change the >> /knowledge/ contained within such a store, or not? > > Not. > >> >> To speak it differently, I've never heard of Joe, and >> (unexpectedly) received a bit of information that speaks: Joe >> has a dog. Now, I receive another bit, that says exactly the >> same. >> >> I'm quite certain that after I've received the first bit I now >> have a bit more knowledge about the World. However, I'm not so >> sure that the second bit gives me any more knowledge, since I >> still have no rational means to tell, whether the dog I'm told >> of this time is the same or different to the one about which >> I've already known. > > Quite. BTW, this would also be true if you had two graphs with URIs instead of blank nodes, even if they were different URIs. > > :joe :has [:dog1 a :dog] > :joe :has [:dog2 a :dog] > > You would still not know that the two different *names* for dogs did or did not name the same dog. Maybe (or maybe not) > > :dog1 owl:sameAs :dog2 > > Pat Hayes > >> >> TIA. >> >> -- >> FSF associate member #7257 > > ------------------------------------------------------------ > IHMC (850)434 8903 or (650)494 3973 > 40 South Alcaniz St. (850)202 4416 office > Pensacola (850)202 4440 fax > FL 32502 (850)291 0667 mobile > phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes > > > > > >
Received on Wednesday, 16 March 2011 17:30:50 UTC