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Re: Reification - whats best practice?

From: Richard Newman <r.newman@reading.ac.uk>
Date: Tue, 31 Aug 2004 09:57:30 +0100
Message-Id: <CA460CF8-FB2B-11D8-BBE5-000A957D9564@reading.ac.uk>
To: rdf-interest <www-rdf-interest@w3.org>

   While you do show that quads can be more compact than triples 
(subject to the inevitable wrangling later on in the thread), I'm not 
sure you're saying the same thing.

   E.g. with reification:

:a1 rdf:type rdf:Statement
:a1 rdf:subject :TheMoon
:a1 rdf:predicate :madeOf
:a1 rdf:object :Cheese
:John ex:said :a1

   Your example with quads:

st1 :TheMoon :madeOf :Cheese
:John ex:said st1

   Thanks to the RDF spec, we know that the former does not suggest that 
the moon is actually made of cheese; that would need another statement. 
However, with the quads we are unable to discern whether or not the 
contained triple is asserted or not; presumably in your example, the 
triple is supposed to be true, while in this it is not intended to be.
   Thus, quads can be ambiguously used as an alternative to explicit 
reification ("John said x y z"), but also to refer to a particular 
asserted statement ("x y z came from B"). How can these two cases be 
distinguished? Do we need another triple pointing to the quad to mark 
it as asserted?
   While [1] might not say that quads are not always a suitable 
replacement, I hope this suggests that they might not be!

   Reification can be bloated, and it doesn't allow us to refer to a 
particular triple. However, quads have their own problems which render 
a general, under-specified approach quite unsuitable.


On 30 Aug 2004, at 09:33, Leo Sauermann wrote:
>  Please - as previously pointed out [1] quads are not always a 
> suitable replacement for reification.
>  I do not think that the quote [1] does point out this. [1] just 
> contains a theoretical assumption about "bloating" that I will falsify 
> below.

> I assume that bloating means "too many triples, they look ugly"
> Ok, I want to see If this assumption is true (theoretically it sounds 
> good,
> but I want to move from theory to reality. This is not much work, 
> actually)
Received on Tuesday, 31 August 2004 08:58:28 UTC

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