- From: pat hayes <phayes@ai.uwf.edu>
- Date: Thu, 17 Apr 2003 12:21:04 -0500
- To: Jim Hendler <hendler@cs.umd.edu>
- Cc: "Jonathan Borden" <jonathan@openhealth.org>, "webont" <www-webont-wg@w3.org>
>At 6:20 PM -0400 4/16/03, Jonathan Borden wrote: >>As I recall the discussion at the Amsterdam F2F -- I had wondered if such >>features would be needed by biomedical ontologies and thought that I was >>told that this wasn't the case. >> >>The use cases he cites are compelling (at least to me), and if indeed >>qualified cardinalities *are* needed to support these then I strongly >>support reopening the issue. I agree. Seems to me that its up to those who think not, to respond to Alan's examples with counter-arguments, eg showing that the workarounds that he dislikes aren't so bad after all, or that there are better ones. >>Jonathan >> > > >I am worried that the feature most complained about in Daml+oil and >also the ones most misused were these. On the other hand, maybe that was partly due to the truly awful terminology used, and the fact that the DAML tutorials placed very little emphasis on them. And that this whole ontology thing was new to many DAML users, whereas Alan is speaking from a much more sophisticated community. >Let me make a suggestion -- if we were to decide to include these, >we would need to write the one-paragraph, easy to understand >explanation that would go in the Overview -- anyone want to take a >stab at a suggested one? Well, the guide only talks about OWLLite, which has limited cardinality in any case so wouldnt work for Alan's examples, but here goes as a sketch: ------- 3.4a OWL Restrictions allValuesFrom.... someValuesFrom.... minCardinalityFrom: This refer to a class and a number. It generalizes someValuesFrom by requiring at least that number of values for the property to be of the type described by the class. Note that this says nothing about values of the property in other classes. [someValuesFrom P] is equivalent to [minCardinalityFrom P 1] maxCardinalityFrom: this restriction requires that the number of values for the property which are of the type described by the class be no more than the number given. Note that this says nothing about values of the property in other classes. [allValuesFrom P] is equivalent to [maxCardinalityFrom [Complement P] 0] CardinalityFrom: This restriction is provided as a convenience when it is useful to state that there is an exact number of values of a property in a particular class, eg [Hand partOf CardinalityFrom Fingers 5] says that the number of partsOf a Hand that are classified as Fingers must be 5. Note that this says nothing about values of the property in other classes; for example, a hand may also have parts which are the palm and the back, in addition to the 5 fingers. minCardinality: this restriction simplifies minCardinalityFrom by ignoring the class; it simply sets a lower bound on the total number of values of the property, in effect treating the restricting class to be the universe. In OWL-DL, [minCardinality n] is equivalent to [minCardinalityFrom owl:Thing n] for individual properties and to [minCardinalityFrom rdfs:Literal n] for datatype properties; in OWL-Full, it is equivalent to [minCardinalityFrom rdfs:Resource n]. similarly for maxCardinality, Cardinality. ------- > -JH >p.s. Any change that would require us to change every document and >that is exposed by test cases makes me nervous at this late date -- >I'd want to see pretty strong support for the change... > Seems to me that Alan makes a devastating case in favor, and that although it is so late and all, that we will look kind of silly if we don't take it seriously. I wish I had thought of the atria/ventricles example. Particularly as he practically tells us what to do. So, I vote to reinstate. Pat > > > >> >>> >>> The following long message (from [1]) comes from Alan Rector to our >>> comments list, addressing the issue of the qualified constraints - >>> basically, he's asking us to reopen issue 3.2 Qualified Cardinality >>> constraints. Guus and I would like to hear the WG's feelings on >>> this. Since there's no specific document addressed (although it >>> would require changes in every document), Guus and I will handle this >>> email and its response. >>> -JH >>> [1] >>> >>http://lists.w3.org/Archives/Public/public-webont-comments/2003Apr/0040.html >>> > >-- >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 -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes s.pam@ai.uwf.edu for spam
Received on Thursday, 17 April 2003 13:21:12 UTC