W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > November 2003

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

From: pat hayes <phayes@ihmc.us>
Date: Wed, 12 Nov 2003 17:36:14 -0600
Message-Id: <p06001f1bbbd873ed31c6@[]>
To: Dan Connolly <connolly@w3.org>
Cc: w3c-rdfcore-wg@w3.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.
>>  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.

For anything other than rdf:XMLLiteral, yes, because  rdfs:Datatype 
isn't in the RDF vocabulary. Its true you hardly need any RDFS 
machinery in order to do datatyping, though.


>>  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/

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Received on Wednesday, 12 November 2003 18:36:16 UTC

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