Re: [BIONT] Bridging Ontology Task

> After John Barkley's presentation, I’ve been thinking about the way
> "owl:sameAs" can used to establish correspondences at the class
> level or instance level (how to draw a distinction between the two
> levels?). 

In OWL DL, we can use owl:sameAs to say that two individuals (instances) are the same. To say that two classes have the same extensionality (i.e. they contain exactly the same individuals), we can use the owl:equivalentClass property. Using owl:sameAs is forbidden in OWL DL (but allowed in OWL Full, which lets you treat classes like instances. Not recommended, though).



> For example, suppose there is a patient related ontology,
> which has a class called “Patient”. To me, a patient named “John
> Doe” would be considered as an instance of the class Patient. Since
> different hospitals may use different types of identifiers to
> identify their patients (it is possible the same patient has been
> admitted to different hospitals). For example, the patient “John
> Doe” may be identified by his soc. sec. number in one hospital,
> whereas he may be identified by a system-generated id in another
> hospital. To use owl:sameAs construct to establish correspondences
> between different patient ids, does it mean that we have to treat
> each individual patient as a class? Is there a thing called
> owl:sameIndividualAs?

I'm not sure if I understand you correcty. In OWL, if we have the class 'patient' (which might be a subclass of 'person', for example), all of the instances of this class would be symbols for a specific human being (and not for social security number or a entry in the database of the hospital). The URIs might be based on soc. sec. number or some other identifier for practical purposes, but the content of the URI does not matter. If we want to make a statement about the soc. security number of that person, we would have to do so with a (possibly functional) owl:DatatypeProperty. If we want to say that two URIs in different databases are symbols for the same person, we can state this with owl:sameAs.

Ok, you probably already knew all of that, but I just wanted to underline the importance of being ontologically consistent and being as realistically as possible (once again). If the URIs in each database would actually be mere symbols for 'a social security number we use as an ID' and 'a database entry we use to identify patients', we could not use owl:sameAs, as both things are wholly different.

(sorry for bringing that up again)

// Matthias

Received on Monday, 12 June 2006 16:52:09 UTC