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ACTION 2002-08-23#7 - "assertion"

From: Frank Manola <fmanola@mitre.org>
Date: Fri, 23 Aug 2002 16:59:27 -0400
Message-ID: <3D66A22F.1090504@mitre.org>
To: RDF core WG <w3c-rdfcore-wg@w3.org>

Re: 
http://www.ninebynine.org/wip/RDF-basics/2002-08-05/Overview.htm#section-Social

ACTION 2002-08-23#7, FrankM:  Propose alternative text for the concepts 
and abstract model document to rectify concerns with conflicting use of 
"assertion".

To state the problem:

The last sentence but one of Section 2.3.1 says "The RDF model theory 
treats RDF as a simple assertional language, in which each triple makes 
a distinct assertion...".

The last sentence of the first para of Section 2.3.2 says "A combination 
of social (e.g. legal) and technical machinery (protocols, file formats, 
publication frameworks) provide the contexts that fix the intended 
meanings of the vocabulary of some piece of RDF, and which distinguish 
assertions from other uses (e.g. citations, denals or illustrations)."

It seems to me someone might read the first bit as saying "all triples 
are assertions" and the second bit as saying "some triples are not 
assertions" (e.g., "denals" [sic]), and then wonder what's going on.

The main problem is that the first bit (taken from the model theory) is 
taken out of context, since there are a number of caveats elsewhere in 
the model theory, e.g., "This only applies to uses of RDF that are 
intended to be the assertion of simple propositional content."

Here's my suggestion:  basically, add some stuff to the beginning of the 
first paragraph so it reads something like:

2.3.2  Social meaning

While the formal semantics of an RDF statement (triple) is that of a 
distinct assertion, individual RDF statements may have a social 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' is true" contains the statement "George is a clown" and, 
considering only that statement, "George is a clown" is a distinct 
assertion.  However, considering the whole sentence, this wouldn't be 
considered an "assertion" (in the socially-understood sense of that 
word) that "George is a clown".  Similarly, a collection of RDF 
statements could be specified in a circumstance in which the social 
meaning was that they were not "assertions", but rather falsehoods 
(e.g., a collection of RDF statements describing a web page entitled 
"famous Internet myths").  At the same time, however, it is important to 
understand that RDF/XML documents, i.e. encodings of RDF graphs, *can* 
be used to make representations of claims or assertions about the 'real' 
world. RDF graphs may be asserted to be true, and such an assertion 
should be understood to carry the same social import and 
responsibilities as an assertion in any other format (including an 
assertion in a natural language document such as a contract). A 
combination of social (e.g. legal) and technical machinery (protocols, 
file formats, publication frameworks) provide the contexts that fix the 
intended meanings of the vocabulary of some piece of RDF, and which 
distinguish assertions from other uses (e.g. citations, denials or 
illustrations).

On looking again, I also have a problem with the second paragraph, i.e., 
the one that says:

"For example, a media type, application/rdf+xml [RDF-MIME-TYPE ] is 
being registered for indicating the use of RDF/XML that might be 
published with the intent of being such an assertional representation 
(as distinguished from other XML or text that may just happen to look 
like RDF assertions)."

The way this whole paragraph follows the first one, it suggests that the 
media type will distinguish between uses of RDF that are intended to be 
assertions, and uses of RDF that have other meanings "(e.g., citations, 
denials, or illustrations)".  Then the parenthetical remark at the end 
comes along: "(as distinguished from other XML or text that may just 
happen to look like RDF assertions)", which suggests that this is a 
purely technical issue, to disambiguate RDF from text that might "happen 
to look like RDF assertions".  I'm not sure this is the same thing. 
What I suspect this is saying is that someone might publish RDF 
statements in RDF/XML with the intention that these be interpreted as 
*other* than assertions (e.g., denials), and that some other media type 
will be used to indicate that;  the media type application/rdf+xml is 
reserved for RDF/XML that is not only RDF/XML, but is intended to 
represent "real assertions".  I suppose you can use the media type that 
way if you want to, but I would argue that characterizing RDF/XML 
published with the deliberate intent of representing a bunch of denials 
as "other XML or text that just happens to look like RDF assertions" is 
highly misleading.  If what I suspect you to mean is what you *really* 
mean, it would be clearer to state explicitly that the media type is to 
distinguish RDF intended to be interpreted as assertions in the social 
sense from RDF intended to be interpreted in some other way.

(I know there was some discussion at the telecon about the media type 
business, but I missed whether it covered this particular issue or not).

--Frank





-- 
Frank Manola                   The MITRE Corporation
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mailto:fmanola@mitre.org       voice: 781-271-8147   FAX: 781-271-875
Received on Friday, 23 August 2002 16:45:16 EDT

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