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Re: Test case document, simple entailment: preferred option.

From: Dan Connolly <connolly@w3.org>
Date: Fri, 07 Nov 2003 17:14:13 -0600
To: Jan Grant <Jan.Grant@bristol.ac.uk>
Cc: Jos De_Roo <jos.deroo@agfa.com>, RDFCore Working Group <w3c-rdfcore-wg@w3.org>
Message-Id: <1068246853.1600.854.camel@dirk.dm93.org>

On Fri, 2003-11-07 at 16:11, Jan Grant wrote:
> One final option has occurred to me, which may have merit.

Seems like a good balance between quick-and-dirty and squeaky-clean.

> Currently the reason that there may be multiple entailmentRules
> specified for an entailment test case is to allude (strongly) to the
> idea that support for different styles of reasoner as one "moves up the
> stack" can be built by adding additional sets of axioms on top of
> previous layers.
> 
> That may or may not actually be the case; however, for the purposes of a
> test case manifest, we need only a single "constant" value to indicate
> (via indirection) _all_ the entailment rules that should be held to be
> in force.

yup.

> That is, currently an RDFS-entailment test is expressed by saying
> (effectively) that both the rdf- and rdfs-entailment axioms are
> in effect.
> 
> This idea is perhaps past its prime; thus, for the purposes of
> selecting entailment rules, the cardinality of test:entailmentRules
> should be exactly one, to choose between entailment tests that are:
> simple, rdf, rdfs, or datatype-aware (which implies rdfs entailment).

er... really? datatype-awareness implies rdfs? I wasn't
aware of that. I'm not at all sure I believe it.

> The point about datatype selection in the last case being closed-world
> is still true. To really deal with that, the expression of
> "supported datatypes" should be done using a parseType=collection-style
> rdf:List.

that appeals to my intuition, though we haven't finished our
cwm-based harness work, so I can't say with much confidence
whether I need it.

> 
> 
> Again, this involves some changes to the test case document, together
> with changes to manifest files. The largest changes are to the
> descriptions of datatype-aware test cases. It is "correct" in that it
> still does away with the closed-world clunkiness of the previous format;
> for the purposes of selection of test cases of a particular type, a test
> case harness that's built around an rdf graph will require fewer
> changes.
> 
> Looking at the WebOnt test cases for impact:
> 
> - WebOnt don't use test:entailmentRules, they utilise their own "level"
> property (with values "Lite", "DL", "Full"); therefore a change to this
> property will have no effect. (This applies to all options).
> 
> - WebOnt use a simple (non-List) format for datatype suport
> declarations. This property is defined by WebOnt's test case format
> without reference to the RDF Test case schema, so would also be
> unaffected. (This applies to all options).
> 
> 
> In summary, there are a number of options to attempt to fix the
> "closed-worldness" of the test case manifest format. Alternatively, the
> "minimal" change would be to disregard DanC/Sandro's closed-world
> issue. (It perhaps behooves the WG to not put its name to a document
> which adopts a worldview antithetical to RDF.)
> 
> The test cases themselves would remain essentially unchanged. The
> description of those test cases is moved towards being a more "correct"
> application of RDF.
> 
> In any case, I can only apologise to the WG that this has arisen as an
> issue so late in the day;

On the contrary! Your attention to detail
throughout the lifetime of this WG is exemplary.

The WG made the "we're ready for PR" decision together.
We could have given you more time for this sort of thing,
but we didn't. We could have decided to do a Call For
Implementations and have a nice liesurely CR period in
which to work out these details, but we didn't.

We accept that we could make this stuff better forever,
but eventually, you gotta shoot the engineers and ship it!

I'll take your apology as evidence that you're taking
seriously the decisions delegated to you by the WG,
but I really don't see anything to apologize for.

>  I resisted my urge to put such a change on the
> agenda for a long time because the authors of test case harnesses
> appeared happy with the status quo, and I didn't want to spring extra
> effort on them while they were doing such an ace job of running our
> tests :-(
> 
> jan
-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Friday, 7 November 2003 18:14:17 EST

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