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Re: "Quick" review of vocabulary document

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Wed, 15 Jan 2003 10:48:55 +0000
Message-Id: <5.1.0.14.0.20030115103050.032dd928@localhost>
To: Graham Klyne <GK@NineByNine.org>, RDF core WG <w3c-rdfcore-wg@w3.org>

Graham,

Thanks for the review.  Detailed comments below.  Out of this, I think 
there is one change I think should be made before last call and that is the 
comment on XMLLiteral should become:

   [[
     The class of XML literals values.
]]

Brian

At 10:20 13/01/2003 +0000, Graham Klyne wrote:

>Reading through this, I noted a number of minor editorial nits, nothing 
>too serious.  My comments here focus on what I perceive to be interactions 
>with the formal semantics.
>
>Reviewing document:
>   http://www.w3.org/2001/sw/RDFCore/TR/WD-rdf-schema-20030117/
>
>I don't think any of the points I raise are definite showstoppers, but I 
>think those labelled "[for discussion]" should be reviewed by the editor 
>before going to last call.
>
>...
>
>[Minor editorial]
>
>Section 1, para 9:
>[[
>This specification does not attempt to enumerate all the possible forms of 
>vocabulary description that are useful for representing the meaning of RDF 
>classes and properties. [...]
>]]
>
>I think "representing" here should be "describing"  (to me, "representing" 
>gets uncomfortably close to the formal concept of denotating, and I don't 
>think that's what is mean here.
>
>I suggest:
>[[
>This specification does not attempt to enumerate all the possible forms of 
>vocabulary that are useful for describing the meaning of RDF classes and 
>properties. [...]
>]]
>
>...
>
>[For discussion]
>
>Section 1, para 10:
>[[
>The language defined in this specification consists of a collection of RDF 
>resources that can be used to describe properties of other RDF resources 
>(including properties) in application-specific RDF vocabularies. [...]
>]]
>
>I don't think it's correct that the *language* consists of a collection of 
>RDF resources.  I suggest:
>[[
>The language defined in this specification consists of a collection of 
>URIs that denote RDF resources that can be used to describe properties of 
>other RDF resources (including properties) in application-specific RDF 
>vocabularies. [...]
>]]

I agree.


>...
>
>[For discussion]
>+
>[Editorial]
>
>Section 2.3 (rdfs:Literal):
>
>I don't think this section sits comfortably with the formal description of 
>rdfs:Literal, which is much less definite about the instances of this class.

The text says:

[[The class rdfs:Literal is the class of literal values such as strings and 
integers.]]

That seems pretty open ended to me.

>"The set of all possible values of all literals is assumed to be a set 
>called LV. Since the set of datatypes is not restricted by RDF syntax, it 
>is impossible to give a sharp definition of LV, but it is required to 
>contain all literal strings, all pairs consisting of a literal string and 
>a language tag, and all values of typed literals." -- 
>http://www.w3.org/2001/sw/RDFCore/TR/WD-rdf-mt-20030117/
>
>I'd suggest wording that is a little more obviously open-ended (see below)
>
>+
>
>[[
>The class rdfs:Literal is the class of literal values such as strings and 
>integers. Property values such as textual strings are examples of RDF 
>literals. Literals may be plain or typed.
>]]
>Is the term "literal values" explained anywhere?  If so, then I suggest a 
>cross-reference;  if not, I'd suggest a more explanatory wording:
>[[
>The class rdfs:Literal is the class of literal values (i.e. values that 
>can be denoted by literals), including the likes of strings and integers.
>]]
>
>(Also note:  in my comments to the semantics document, I question whether 
>there really is a distinction between the set of literal values and 
>resources in general.)

I think we can take this as word smithing in last call.


>(Also, as noted below, I am uncomfortable with the phrase "property value".)
>
>...
>
>[For discussion/editorial?]
>
>Section 2.3, 3.1, and elsewhere I think:
>
>There are a number of references to a "property value" or "the value of a 
>... property" meaning the thing denoted by the object of a statement 
>containing a given property.  When I see the term "property value", or 
>similar, I tend to think of the denotation of the property itself.  It 
>would be good to find a snappy phrase that didn't have this potential 
>misinterpretation.
>
>Maybe:  "property object value" or "the object value of a ... property"?

Lets see in last call how many folks get confused.  I find your 
misunderstanding rather hard to understand, but we might come up with 
clearer text later.


>...
>
>[For discussion]
>
>Sections 3.6, 3.7:
>
>It's not clear what are the implication for the domain of rdfs:label and 
>rdfs:comment being rdfs:Literal.  I think some people might read this to 
>mean that any occurrence of these properties must be syntactically with a 
>literal object.  I don't think that is correct.

I don't understand this comment.  The semantics of domain and range are 
pretty clear, no?  I think its a mistake to start speculating about folks 
misunderstandings.  Thats a game we could play forever.

>I think it would help to be clearer about this;  e.g.
>
>[[
>The range of this property being rdfs:Literal means that its object value 
>must be something that can be denoted by a literal;  in normal use, the 
>object will be a literal, but this is not a requirement and it is quite 
>valid to use a non-literal resource that happens to denote some literal value.
>]]
>
>In all, I think the rdfs:Literal range constraint is semantically very 
>weak.  My concern is that it is mistaken as a syntactic constraint.
>
>...
>
>[Editorial]
>
>Section 5.3:
>
>[[
>The original RDF Model and Syntax Specification [RDFMS] defined vocabulary 
>for describing RDF statements without stating them.
>]]
>
>I think the term "stating" here may be not understood.

The 'stating' is consistent with the language used throughout this 
document.  I'm inclined to leave it alone or change all of it, and I don't 
want to change all of it at this stage.

>  I suggest:
>
>[[
>The original RDF Model and Syntax Specification [RDFMS] defined vocabulary 
>for describing RDF statements without asserting them (in the sense of 
>[x-ref to Semantics Glossary, "assertion"]).
>]]
>
>...
>
>[For discussion]
>
>Section 6.1:
>
>rdfs:Literal -- see comments above.  I suggest the comment might be:
>[[
>The class of literal values, including values such as textual strings and 
>integers.
>]]
>
>(I'm trying to offer wording that is more suggestive of an open-ended set 
>of values.)
>
>rdf:XMLLiteral -- I think the comment is not quite right -- it seems to 
>admit any syntactically valid piece of XML;  I suggest:
>[[
>The class of XML literal values;  i.e. canonical XML (cf. denotation of 
>"xxx"^^rdf:XMLLiteral in semantics document, section 3.1).
>]]

I agree it should the class of xml literal values.  I recommend we fix that 
before it goes.


>...
>
>Appendix A, not checked.
>
>
>
>-------------------
>Graham Klyne
><GK@NineByNine.org>
Received on Wednesday, 15 January 2003 05:47:37 EST

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