RE: [OEP] Draft of a note on n-ary relations

Natasha, Alan

Nice work, once again :)

Some remarks about Pattern 2.

- The property "amount" seems to me a Datatype property, but it is displayed in the
graphical representation
the same way as otherwise Object properties, and further on not mentioned in the
So it does not seem to really participate in the relationship, or in a different and
underspecified way.
This is potentially confusing.
I would suggest to either get rid of it altogether (the example seems complex and
illustrating enough without it),
or specify how "amount" is different from other roles in the association. (Sorry, topic
map terminology is coming here very naturally - see below).

- Why is there not any inverseOf for "purpose"?

- The pattern looks much topic-map-ish to me ... A translation in terms of Topic, Roles
and Associations is quite obvious and easy to do. Note that in a topic map representation,
the inverse properties would be useless, since the linking of a topic to an association
through a role is by nature two-ways.
Only the instance of Purchase could be expressed easily this way in XTM, while the
reference pattern could be in the OWL ontology. I made proposals for such mechanism in my
XML Europe 2004 paper "Ontology-Driven Topic Maps"

I can provide TM translation for the Lionish example, along the lines of this paper, and a
bit of XTM syntax if it considered relevant to include it in the document.



Bernard Vatant
Senior Consultant
Knowledge Engineering
Mondeca -

> -----Message d'origine-----
> De :
> []De la part de Natasha Noy
> Envoye : mercredi 5 mai 2004 03:16
> A : swbp
> Cc : Alan Rector
> Objet : [OEP] Draft of a note on n-ary relations
> People seem to have agreed that doing a pattern on n-ary (reified)
> relations would be a useful thing to have. Alan Rector and I actually
> had a chance to work it out and you can see the first draft  of our
> effort at
> aryRelations.html
> It's nowhere near as complicated or as controversial (we hope) as the
> Classes as Values one. In fact, it's rather simple, almost too simple
> to be a pattern. On the other hand, it seems to be on a topic that many
> newcomers to OWL have questions on.
> As usual, please feel free to poke holes in it and all feedback is
> welcome.
> Thanks in advance,
> Natasha and Alan

Received on Wednesday, 5 May 2004 08:46:57 UTC