Regrets (was Re: agenda, 17 october, 14:30 UTC)

Regrets; I'm being kidnapped by pterodactyls.

No! Wait, it's worse than that. I'm withdrawing from the group, and,  
at the moment, there is no replacement from Manchester, I'm afraid.  
Basically, I just can't keep up given some other, unavoidable,  
responsibilities and my current stamina.

I certainly learned a lot, which is a good thing. I think I also  
helped nails some stuff down that wasn't so very nailed down, which  
is also a good thing. Good luck to getting it done. Hope to meet up  
with folks at ISWC

===============

Few quick thoughts to kinda wrap stuff up:

1) The current semantic framework can be repaired for both its over  
and under counts. The first (which Jorge pointed out) I think Pat is  
on top of, the latter (which Eric's been harping on) can be handled  
(I believe) by extending the notion of a solution to include a  
justification, that is, a minimal subset of the graph sufficient to  
entail the binding. (Obviously, you won't *return* these in the  
normal case, but, in a sense, that's what's actually going on in  
graph matching and it scales smoothly to description logics; however,  
for DLs, for non-counting situations, you will want to be a little  
less restrictive on what systems are forced to return.)

2) I would just adopt the SCS algebra. It's clear, neat, and well  
done. Jorge I'm sure would be happy to help out.

3) To that end, I would do what many have suggested in having a more  
abstract language that is the object of the semantics. I would make  
it so that there was as little implicit as possible.

4) I think the turtle is confusing because of the weakness of the  
constraints it imposes. OTOH, if y'all do keep it, then I would hope  
that it stays as closely aligned in *semantic* flavor to turtle and  
turtle supersets. Essentially, this is another argument for  
commutativity.

5) If you do go back to graph matching, please be *very* cautious  
with what you claim for it. There are many issues about applying it  
to RDF and RDFS (see contradictions!) as a specification mechanism.  
It would be nice if the text made the interface between the BGP and  
the algebra very distinct so we could 1) swap in an arbitrary other  
*specification* mechanism and 2) thus alternative semantics.

At OWLED, after ISWC, Kendall and I will be discussing SPARQL with a  
fairly serious subset of the OWL community:
	http://clarkparsia.com/weblog/2006/10/13/owled-2006-is-nigh/
	http://owl-workshop.man.ac.uk/programme06.shtml

Always good to have more!

Cheers,
Bijan.

Received on Tuesday, 17 October 2006 13:39:00 UTC