Re: Requirements for a possible "RDF 2.0"

On 2010-01-14, Toby Inkster wrote:

>  * Explicit support for named graphs

Yes, this would be a step forward. But if you look at them from the 
logical or the semantic point of view, they are simply another 
instantiation of reification. If we want to give them a proper axiomatic 
semantics, we're right back into the debates which surrounded 
reification from the get go.

Make no mistake, I think named graphs are a *very* good idea. I just 
think we might be glossing over a number of minutiae by calling 
wholesale reification by another name, and just hoping those pesky 
logicians don't catch upto our newest fad. ;)

>  * Literal subjects

Personally I'd like to see subject, predicate and object, all of them, 
handled on an equal footing. Or if not, I'd like to see an axiomatic 
semantics which clarifies their inherent difference.

>  * Blank node predicates

Absolutely. Even if nothing else, blank nodes should be allowed in 
subject, predicate and object. I mean, from my relational database 
background, I tend to think of blank nodes as the perfect, Coddian, 
blind surrogate. In that sense, they can serve in any role at all.

> (Though it might be a good idea to phase out blank nodes.)

>From my viewpoint, I tend to disagree. Even in the relational mindset 
they have served well, and RDF's blank node abstraction is perhaps the 
purest implementation of the surrogate concept thus far. We should not 
throw it out simply because it makes things a bit more complicated -- 
instead we should clarify the semantics of it, and further utilize stuff 
like unique properties and other contextual clues to merge various blank 
nodes into one.
Sampo Syreeni, aka decoy -,
+358-50-5756111, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2

Received on Thursday, 14 January 2010 19:20:47 UTC