[foaf-dev] Time to make the foaf classes relate to Dublin Core classes?

Richard Cyganiak richard at cyganiak.de
Wed Jan 23 12:24:18 GMT 2008


On 23 Jan 2008, at 00:13, Dan Brickley wrote:
> Thanks for raising this. I agree that the two classes have the same  
> members. Had a chat with Tom Baker earlier too, and we couldn't  
> think of any example "agents" that these two definitions would  
> disagree about. The owl:sameAs relation, however, would be too  
> strong, since the classes are different beasts. They have different  
> history, provenance and other facts about them.

That's an interesting point of view. You've stated before that classes  
and properties are “creative works”. Here you state that classes and  
properties have history and provenance.

I don't like this point of view. It violates Occam's razor and muddles  
a bunch of things.

I offer an alternative view here:

RDFS classes and properties cannot exist without documents describing  
and defining them. This could be RDFS documents or prose  
specifications, like the FOAF spec. Thus, the history and provenance  
of classes and properties can be tracked by looking at the documents.  
The documents also clearly are creative works.

Hence, I think it is much simpler, clearer and more natural to ascribe  
history, provenance and expression of creativity to the documents that  
define classes and properties; not to the classes and properties itself.

After all, it is clear and undeniable that the FOAF specification is a  
creative work of yours. It is also undeniable that this specification  
describes a class, foaf:Person, which contains all people. But do you  
really want to claim that you are the creator of the class of all  

As I see it, this class has always existed “out there”, and the  
contribution of you and the DC folks is that you've described this  
existing class with a certain level of formality, and given it a URI.  
You did this by creating a document.

My argument boils down to this: It is futile to talk about who created  
a particular abstract concept, or try to track versions of an abstract  
concept. Let's stick to observable reality -- to the documents that  
describe the abstract concepts. We know who created them, we can  
version them. I think that this view of the world avoids a whole bunch  
of thorny philosophical issues and is healthier for getting stuff done.


> But reciprocal subclass claims, or other OWL statements to same  
> effect, would be fine. I've talked a few times with Tom about  
> signing of RDF statement for this sort of thing, but for now I'll  
> just add this to the next rev of the FOAF spec, unless anyone can  
> come up with a counter-example.
> cheers,
> Dan
>> /Mikael
>> [0] http://dublincore.org/news/2008/#dcmi-news-20080114-01
>> [1] http://dublincore.org/documents/dcmi-terms/
>> [2] http://dublincore.org/schemas/rdfs/
>> [3] http://dublincore.org/documents/domain-range/
>> -- 
>> <mikael at nilsson.name>
>> Plus ça change, plus c'est la même chose
>> _______________________________________________
>> foaf-dev mailing list
>> foaf-dev at lists.foaf-project.org
>> http://lists.foaf-project.org/mailman/listinfo/foaf-dev
> _______________________________________________
> foaf-dev mailing list
> foaf-dev at lists.foaf-project.org
> http://lists.foaf-project.org/mailman/listinfo/foaf-dev

More information about the foaf-dev mailing list