- From: Jeremy Carroll <jjc@hpl.hp.com>
- Date: Tue, 13 Nov 2007 15:51:54 +0000
- To: Alan Ruttenberg <alanruttenberg@gmail.com>
- CC: public-owl-wg@w3.org
Alan Ruttenberg wrote: > I'm not sure how to characterize the interactions. For instance there > are issues around combining cardinality restrictions with transitive > roles that can be triggered on a merge. These can only be triggered when the two ontologies being merged each contain one or more axioms mentioning a proeprty in common, and those axioms violate some condition. And ditto with your other examples. In the Pan and Horrocks version of the n-ary datatypes, the datatypes used in an ontology, as a whole, form a datatype group, and so if one ontology mentions decimal-multiplication, another decimal-addition, and a third integer (as a subtype of decimal), the merge of all three is non-conforming - even though the only common thing they have is the builtin decimal - which is not modified by any of the ontologies. This has the potential to give a much worse user experience. On the other hand, the approach used by racer is likely to be somewhat betetr behaved, but the formal properties seem significantly less clear. > > Speaking as a user, I don't currently have the expectation that the > merge of two OWL-DL ontologies will yield yield an OWL-DL ontology. No - but what about two almost completely independent OWL-DL ontologies? > My > gut is that we don't want to make this a restriction as we would land up > over constraining our ability to add useful features. > I am not suggesting it as a general restriction - more as a pertinent restriction in this case - largely because there is a need for more theoretical work. > More merge issues come up with subproperty chains. > > Regarding N-ary datatypes, for the first part of this I think we need to > start talking about this in a way that people might understand. Vipul, > when he raised the question of working with linear inequations in OWL, > did not recognize the connection to N-ary datatypes. To me, this > adequately demonstrates that we need to rephrase how we discuss this > feature in the specification and in our documentation. > > I'm pretty sure that most application developers would gladly trade some > risk on merge for the ability to have linear inequations in OWL, but we > could certainly test that with a survey. Agreed. The problem is quatifying the 'some' in 'some risk'. Also the n-ary datatypes design is much much more general than linear inequations - the member submission design is not a proposal to integrate linear programming with OWL Jeremy
Received on Tuesday, 13 November 2007 15:52:32 UTC