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RE: Comments on the new RDF Test Cases draft

From: Massimo Marchiori <massimo@w3.org>
Date: Wed, 29 May 2002 12:43:28 -0400
Message-Id: <200205291643.MAA06288@tux.w3.org>
To: bwm@hplb.hpl.hp.com, phayes@ai.uwf.edu
Cc: www-rdf-comments@w3.org


> When I said no, I was thinking of parser tests, which in practise is what 
> people will be using the tests for.  I think I was wrong as the question 
> Massimo asked was not well formed.
> 
> We are not defining any notion of compliance, so there is no 
> answer.  We do 
> say, that for a given test case, the input RDF/XML represents the same 
> graph as the supplied n-triples.  That is syntactic equivalence and that 
> seems right to me.  Notions of semantic equivalence can be kept separate.
> 
> Sorry, Massimo; I was in too much of a hurry answering your mail 
> and failed to engage brain above first gear.

Ok, that's a reasonable way out: don't give any conformance status to the Test Cases. 
In this case, my suggestion is to smoothen the current language (which now can
lead to think there's some normative conformance definition creeping in, 
i.e., defining normatively conformance of an "RDF parser").
In particular, whereas now there are wordings like
+ for positive tests:
<quote>
A parser is considered to pass the test if it produces a graph isomorphic 
with the graph described by the N-triples output document. 
</quote>
+ for negative tests:
<quote>
A parser is considered to pass the test if it correctly holds the input document to be in error. 
</quote>

more milder words can be used, for example using something like 
"the expected output of an RDF parser is a graph ... bla"
which conveys the intuition that, reasonably, a parser should do what stated here,
but doesn't normatively try to impose some notion of "test passing" for parser
(which leads to conformance, which leads to the syntactic/semantic issue, and/or
to a definition of what an RDF parser is....).
For the negative tests, similar thing, like e.g., "the expected behaviour of an RDF 
parser is to raise an error".

Note the entailment part, on the other hand, does a good job to avoid the 
"conformance problem", as it writes rather neutrally:
<quote>
the test succeeds if the entailment holds
</quote>
(i.e., the "test" is made the subject of the sentence).

Therefore, such "word smoothering", plus a precise definition of isomorphism,
suffice. But, note that if we go along the "smoothering way", the same problem of
a precise definition of isomorphism can be nicely dropped as well, as the wording can 
well say that the "expected output" is the given N-triple one, and just be
silent on the isomorphism issues at all (as, it's rather clear that N-triple
output is defined modulo renaming of blank nodes, and in any case, crucially, no 
*formal* definition is then needed as the Test Cases contain clarification guidelines,
and not formal normative definition of "test passing for parsers").

-M
Received on Wednesday, 29 May 2002 12:44:05 GMT

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