- From: Deborah McGuinness <dlm@KSL.Stanford.EDU>
- Date: Thu, 15 Aug 2002 13:51:39 -0700
- To: Guus Schreiber <schreiber@swi.psy.uva.nl>
- CC: WebOnt WG <www-webont-wg@w3.org>
Are we agreed that we will be using this format? I have no objection (although make an augmentation suggestion below) but I am about to write up a simple closed world notion using cardinality and wanted to use the accepted format. I had previously started to collect "tricks of the trade" how to do it cases and had posted http://www.ksl.stanford.edu/people/dlm/daml/modelingIssues.html which contained a short writeup for capturing a notion of same-as. That was last updated nov 2001 and had the format task observation (optional) abstracted solution daml+oil solution references acknowledgements my task is guus's modeling problem, my abstracted solution is basically a typical solution daml+oil code (or owl code now) could be in an appendix but it will probably be heavily used for cutting and pasting so i suggest that we add this to guus' template. are there other refinements/suggestions people have? it will be easier for us if we get these out now before too many submissions are made. thanks, deborah Guus Schreiber wrote: > FORMAT FOR OWL HOW-TO-DO-IT GUIDELINES > First draft, July 21 > > TITLE > MODELLING PROBLEM > - should include domain-specific example > - should explain why modelling of this feature is not straightforward in OWL > - include criteria required for this pattern to apply > TYPICAL SOLUTION > - modelling approach for the example > - pattern: how to do this in general > HINTS & TIPS > - hints about typical modelling decisions > - links to other patterns > KNOWN USES & REFERENCES > - links to applications that use this > - links to relevant literature > > TITLE Bi-directionality of relations between classes > > MODELLIN PROBLEM > > OWL properties differ from, for example, UML associations in the sense > that OWL > properties are directional (from subject to object) and thus models an > association "from one side". > > Take for example the following UML association. > > [@@ Include fig with association "enrolment" between a student and a > course.] > > In OWL, we would need to decide on the direction of the association, > e.g. that the property goes from student to course. Also, adding > cardinality (= multiplicity) constraints can only be done in OWL for > one side of the association:. If the property is defined as student => > course, you can say how many courses a student may be enrolled in, but > you cannot say how many students may be enrolled in a course. > > TYPICAL SOLUTION > > If you really need the "bi-directional" view on the association, > you could define two properties, where one is the inverse of the > other: > > [@@ include owl language fragments for the example] > > So in general, if you have a UML relation which is navigable from both > sides, consider modelling it the following way in OWL: > - Define two properties and define one of them as the "owl:inverseOf" > the other property. > - Choose directional names for the properties, similar to role names > in a UML association > - Attach range and cardinality constraints to the respective > properties. > > HINTS & TIPS > > - Define the least frequently-used direction as the "inverseOf" > property. > - @@ > > KNOWN USES & REFERENCES > > @@. > > -- > A. Th. Schreiber, SWI, University of Amsterdam, > Home page: http://www.swi.psy.uva.nl/usr/Schreiber/home.html -- Deborah L. McGuinness Knowledge Systems Laboratory Gates Computer Science Building, 2A Room 241 Stanford University, Stanford, CA 94305-9020 email: dlm@ksl.stanford.edu URL: http://ksl.stanford.edu/people/dlm/index.html (voice) 650 723 9770 (stanford fax) 650 725 5850 (computer fax) 801 705 0941
Received on Thursday, 15 August 2002 16:50:42 UTC