- From: Steffen Staab <staab@uni-koblenz.de>
- Date: Wed, 13 May 2009 09:21:17 +0200
- To: Pat Hayes <phayes@ihmc.us>
- CC: David Baxter <retxabd@gmail.com>, semantic-web@w3.org
Here is a great account of this problem: http://www.aaai.org/Library/AAAI/2007/aaai07-044.php though it is not straightforward to capture this in OWL Steffen Pat Hayes schrieb: > > On May 12, 2009, at 9:06 AM, David Baxter wrote: > >> Pat Hayes said: >> >> > I know both Cyc and dbPedia say their >> > concepts are sameAs one another, but they are both wrong. Cyc defines >> > a 'piece' of carbon; dbpedia defines the chemical element carbon. >> > These concepts are NOT owl:sameAs one another, no matter what the >> > websites say. >> >> >> Hi Pat, >> >> We're definitely interested in improving the quality of our owl:sameAs >> links to DBpedia and other datasets. In this case, however, I believe >> the owl:sameAs link is good -- it's the OpenCyc comment that's bad. >> The URI opencyc:Carbon >> <http://sw.opencyc.org/concept/Mx4rvVjIQpwpEbGdrcN5Y29ycA> denotes an >> owl:Class representing the element carbon. Its instances are >> individual pieces of carbon, including diamonds and lumps of coal. >> We'll get the comment fixed. > > Hmm. So - just to see if I follow you here - Cyc thinks that a chemical > element *is* the class of all its macroscopic pieces? Is this what > DBpedia also thinks a chemical element is? Because (a) that seems to me > to be a very idiosyncratic view of what a chemical element is, and (b) > if DBpedia has some other ontology of chemical-element-hood, then your > two concepts are very unlikely to the sameAs one another. Bear in mind > that owl:sameAs really does mean logically identity, so ANYTHING said > using one name is true using the other. So someone should be able to > take any DBpedia content mentioning carbon, and any piece of Cyc content > mentioning carbon, substitute one carbon name for the other throughout > both chunks, and conjoin them, and the result ought to make sense in > both systems. Is that indeed true, in this case? > > Pat > > PS. What does Cyc do about elements which only exist macroscopically as > compounds? If there are no pieces of pure Ytterium, say, then the class > Ytterium is the empty class. If there are no pure samples of > Einsteinium, similarly. In an OWL reasoner, you could infer that they > are the same class, hence sameAs one another (since they are both classes). > >> >> David Baxter >> Cycorp > > ------------------------------------------------------------ > 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, 13 May 2009 07:21:52 UTC