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RDFCore last call WD's: Two comments on the RDF documents

From: Bob MacGregor <macgregor@ISI.EDU>
Date: Tue, 28 Jan 2003 12:05:09 -0800
Message-Id: <5.1.1.6.0.20030128120429.00b79818@tnt.isi.edu>
To: www-rdf-comments@w3.org

In examining the RDFCore documents, I have found two sections where I believe
the language needs to be rewritten.


In the excerpt below from the RDF Primer, I believe that the use of double
brackets in the example is misleading, and should be replaced by something 
else.
It illustrates a statement syntactically nested within another 
statement.  There
is nothing in the current RDF equivalent to such a construct.  It preceeds a
discussion of reification, which might lead a reader to believe that RDF's
notion of a reified statement (a "stating") is somehow related to this kind of
nesting.

     RDF Primer
     4.3 RDF Reification
     Now, suppose we wanted to say in RDF that this statement was made by John
     Smith. Since in RDF we can only make statements about resources, what 
we would
     like to be able to do is write something like:

      [[exproducts:item10245  exterms:weight  "2.4" .]] 
dc:creator  exstaff:85740 .

Here are two quotes from Pat Hayes' emails:

" ... rather like saying that the
ability to sing eliminates the need to stand on one foot. Nesting hasn't got
anything to do with reification."

"Many people have suggested using reification to simulate expression nesting in
recursive syntax, but this kind of usage for reification was a mistake from the
start."

Pat is claiming that reification and nested statement syntax have nothing to do
with each other, while the excerpt from 4.3 uses nesting as a lead-in to a
discussion on reification.  While my personal belief is that there IS a
connection, I will affirm that nested statements do not correlate with the
notion of a "stating" that RDF has adopted.  Hence my recommendation that
the example of nested syntax be replaced by something else.



I have a problem with the following discussion in the Concepts and Abstract 
Syntax
document:

     Concepts and Abstract Syntax
     4.1 Asserted and Non-Asserted Forms

     Not every RDF/XML expression is asserted. Some may convey meaning that 
is partly
     determined by the circumstances in which they are used. For example, 
in English,
     a statement "I don't believe that George is a clown" contains the 
words "George
     is a clown", which, considered in isolation, has the form of an 
assertion that
     George exhibits certain comic qualities. However, considering the whole
     sentence, no such assertion is considered to be made.

First, I don't believe that the statement "I don't believe that George is a
clown" is expressible in RDF.  I am happy to be proved wrong, in which case
would someone please show me an illustration of it?

Second, the discussion in 4.1 does not provide any examples in RDF of
expressions that are not asserted.  Hence, whether or not the "I don't believe
..."  statement can be expressed, the discussion ought to contain SOME example
in RDF of a non-asserted RDF expression.

Cheers, Bob
Received on Tuesday, 28 January 2003 15:06:41 GMT

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