- From: Christopher Welty <welty@us.ibm.com>
- Date: Wed, 18 Sep 2002 09:49:23 -0400
- To: www-webont-wg@w3.org
Jim, In your example below, that the builder of URI2 may not have "intended" for all of URI1 to be loaded when importing URI1:foo is too bad. One of the most common and (I think) important reasons to build a million-node graph around a set of symbols to to ensure those symbols are used correctly, and to prevent them from being used incorrectly. The ontology helps to enforce that the intended meaning is maintained. If someone wants to import just one symbol from my ontology, then they have to get all of my ontology so that they get all the constraints and inter-relationships that help clarify the meaning of that symbol wrt others. I *don't care* if that's what the user intended - that's what I, the designer of the ontology, intended: dont misuse my symbols! If this isn't enforced, then borrowing symbols from other ontologies is meaningless and serves no purpose. There is nothing to gain from using URI1:foo if you aren't getting all of the ontology around URI1:foo - you may as well just make up your own symbol in URI2, because that's all it is. If you are borrowing URI1:foo because "you mean the same thing", then importing the whole ontology that enforces that meaning should have no bad consequence. Of course ontologies can always be built in a modular way so that if there is a small subset of the symbols that can be exported idependently of others (a top level ontology would be one kind of example) then they are all in a smaller ontology that is imported, but that is more of an engineering issue. -Chris Jim Hendler <hendler@cs.umd.edu> Sent by: www-webont-wg-request@w3.org 09/17/2002 09:57 PM To: pat hayes <phayes@ai.uwf.edu> cc: www-webont-wg@w3.org Subject: Re: LANG: owl:ontology what I have a problem with is the following At URI1: .... <owl:class rdf:ID="foo" /> (1,000,000 other assertions that appear in the graph) At URI2: <:bar owl:subclass URI1:foo /> (put in any owl:ontology and rdf:RDF syntax you want - but no owl:imports in URI2:) In this case I have a real problem with merging the graphs -- the user is very unlikely to actually intend that those million facts which he or she may not even have read should be included. This is the case I really care about. For imports anything that can identify and merge graphs makes me happy - for this case, I care that we somehow scope what is included. I would like this to have the same semantics as having one URI which contained <owl:class rdf:ID="foo" /> <:bar owl:subclass :foo /> (i.e. nothing else from URI1: is to be included unless it is explicitly mentioned.) -- Professor James Hendler hendler@cs.umd.edu Director, Semantic Web and Agent Technologies 301-405-2696 Maryland Information and Network Dynamics Lab. 301-405-6707 (Fax) Univ of Maryland, College Park, MD 20742 240-731-3822 (Cell) http://www.cs.umd.edu/users/hendler
Received on Wednesday, 18 September 2002 09:49:59 UTC