representing null in semantic frameworks

As RDF evolved, was there any discussion on adding an rdf:null 
resource---that is, a resource that represents no resource at all?

One expected response: "My child, you're thinking like a programmer 
again---what you really want to do is assert the absence of any 
assertions regarding a particular subject and predicate, or you want to 
assume a closed world and just don't assert anything at all", or 
something like that---and I appreciate this point of view to some extent.

But as a practical matter, let's say we have a list of baseball game 
scores. Wouldn't it be convenient for the resource at index 3 to be null 
to indicate that there was no score that week because there was a 
tornado that canceled the game?

I'm not necessarily looking for a big online discussion. Just a brief 
pointer to any reading on this subject would help. I'm sure there must 
have been some discussion of null over the development history of RDF.

Thanks,

Garret

Received on Saturday, 20 October 2007 16:16:40 UTC