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Re: "meaningless terms" verbage for Primer

From: pat hayes <phayes@ai.uwf.edu>
Date: Mon, 9 Dec 2002 18:24:38 -0600
Message-Id: <p05111b33ba1ae41795e7@[10.0.100.86]>
To: Dan Brickley <danbri@w3.org>
Cc: w3c-rdfcore-wg@w3.org

>+1 on What Dave Said.
>
>I feel like some of us are on different planets here. Vocabulary
>meaning is not exhaustively accounted for by the MT/inferential story. We
>admit that implicitly when we allow that two classes may have the same
>extension yet be considered usefully different entities.
>Attempting to divide the
>RDF world into 'good' properties (those that are mentioned in some rules
>we've written) and 'bad' ones (the rest) is imho a vast oversimplification
>of the situation.

The good/bad stuff is beside the point. It does however make some 
sense to split the vocabulary into what might be called 
free/restricted, where 'free' means that an implementer can do what 
they like with it, even if we provide some guidance, and still 
conform; but restricted means that conformance requires that they use 
it only in certain ways. On that criterion, rdf:li and rdf:nil would 
be in the restricted category, of course.

Pat

>
>Dan
>
>* Dave Beckett <dave.beckett@bristol.ac.uk> [2002-12-09 13:22+0000]
>>
>>  >>>Patrick Stickler said:
>>  >
>>  > Here is my proposed verbage regarding terms with undefined
>>  > semantics, for inclusion into the Primer. Frank, feel free
>>  > to wordsmith freely.
>>  >
>>  > Note that the list was based on there being no defined semantics
>>  > for the term in the MT, even if there might be range, domain,
>>  > type, or other assertions made about the terms. The list (or the MT)
>>  > may need adjusting if it is incorrect...
>>  >
>>  > rdf:li was not mentioned in the MT, but that may be an omission
>>  > since it's in the syntax doc. It is included in the list
>>  > below.
>>  >
>>  > --
>>  > The RDF/S vocabulary includes several terms the meaning of which
>>  > was undefined or ambiguous in earlier specifications of RDF and
>>  > which remain undefined in the present RDF MT.
>>  >
>>  > Specifically:
>>  >
>>  >    rdf:value
>>  >    rdf:Bag
>>  >    rdf:Seq
>>  >    rdf:Alt
>>  >    rdf:li
>>  >    rdf:_n
>>  >    rdf:List
>>  >    rdf:first
>>  >    rdf:rest
>>  >    rdf:nil
>>  >    rdfs:comment
>>  >    rdfs:seeAlso
>>  >    rdfs:isDefinedBy
>>  >    rdfs:label
>>  >
>>  > These terms remain in the RDF/S vocabulary for various historical
>>  > reasons. Their lack of an explicit or clear interpretation has
>>  > resulted in their being used in incompatable ways by different
>>  > applications. Nevertheless, as they provide utility to certain
>>  > RDF applications, and in the interest of backwards compatability,
>>  > they have not been deprecated or removed.
>>
>>  That's wrong in several ways.
>>
>>      rdf:List
>>      rdf:first
>>      rdf:rest
>>      rdf:nil
>>
>>  These terms are not historical - they are new to this revision of RDF.
>>
>>      rdf:li
>>
>>  Never a property; a piece of rdf/xml syntax scaffolding.
>>
>>      rdf:_n
>>      rdf:value
>>      rdf:Bag
>>      rdf:Seq
>>      rdf:Alt
>>      rdfs:comment
>>      rdfs:seeAlso
>>      rdfs:isDefinedBy
>>      rdfs:label
>>
>>  None of these are deprecated and should not be described in any way
>>  as historical.  They remain used, useful and staying that way.
>>
>>
>>  > Note that some of these terms do have certain constraints defined
>>  > in the MT for their use, such as their domain, range or type, but
>>  > their actual meaning is not specified.
>>  >
>>  > Users should take care when employing these terms, as there is no
>>  > guaruntee that any RDF applications will interpret them as intended.
>>  > It should also be noted that no valid inferences may be drawn from
>>  > statements using these terms, insofar as the model theory is concerned.
>>  > Any interpretation or inference based on these terms is entirely
>>  > application specific.
>>
>>  "no valid inferences"!  Rubbish.  Don't say such things.  Triples
>>  with these terms are valid.
>>
>>  > This document contains examples which reflect how some of
>>  > these terms have been previously used; however such usage is
>>  > merely suggestive and in no way constitutes a normative definition
>>  > of their meaning or purpose.
>>
>>  This is saying again that the primer is informational, but rather
>  > negatively.  The primer is informational and useful; the formal
>>  meanings of the terms are in other docs, which are pointed to.
>>
>>  Dave


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Received on Monday, 9 December 2002 19:25:09 EST

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