Re: why are properties decoupled from classes

Xavier Noria wrote:
> In RDFS and friends properties do not "belong" to classes, whereas in  
> OOP normally they do. For instance, if you've got an instance of  
> foaf:Person you cannot assume there's any assertion about  foaf:interest 
> for him.

Look at it the other way around. If you could assume that there was a 
foaf:interest assserted for every foaf:Person then any foaf:Person 
without a foaf:interest asserted would be invalid, hence it would be 
impossible to say anything about anyone without giving at least one 
foaf:interest which you may neither know nor care about. An application 
concerned with people's medical history will not care about the same 
information as one concerned with their professional qualifications and 
so on.

It *is* possible to say that, for example, all people have mothers, 
however knowing that there is a single value for the 
_ex:biologicalMother property of every person does not mean that you 
will be informed as to who that person's mother is.

Received on Wednesday, 26 October 2005 09:16:15 UTC