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RE: Minor comments on 18 Aug 2003 OWL Guide [attempt 2]

From: Ian B. Jacobs <ij@w3.org>
Date: 03 Nov 2003 08:36:33 -0500
To: "Smith, Michael K" <michael.smith@eds.com>
Cc: public-webont-comments@w3.org
Message-Id: <1067866593.31560.29.camel@seabright>
On Tue, 2003-10-21 at 14:03, Smith, Michael K wrote:
> Ian,
> 
> Thank you for your suggestions.  Please reply to the mailing list 
> as to whether the proposed changes below adequately address your 
> comments with respect to the Guide.
> 
> - Mike
> 
> Michael K. Smith, Ph.D., P.E.
> EDS - Austin Innovation Centre
> 98 San Jacinto, #500
> Austin, TX  78701
> 
> phone: +01-512-404-6683
> email: michael.smith@eds.com
>   
> 
> > 1) Subsections of 3.4 are numbered; subsections of 3.3
> >    are not. I think those of 3.3 should also be
> >    <h3> numbered headers.
> 
> I agree, not sure what historical artifact led to that.  Will fix.
> 
> > 2) Under 3.3, inverseOf, "z" is mentioned in the first
> >    sentence (before the colon) but is not used in 
> >        P1(x,y) iff P2(y,x)
> 
> Will fix.
>  
> > 3) Under 3.3, inverseFuntionalProperty, on the other hand,
> >    "z" is not used in the first sentence but does appear
> >     in 
> >        P(y,x) and P(z,x) implies y = z.
> 
> Will fix.
>  
> > 4) The first few paragraphs of section 4 (Ontology mapping)
> >    seemed to cry out for at least a mention of namespaces.
> >    This comment is not that important, but if there is
> >    more information in another document about ontology
> >    sharing, a reference to it would be helpful.
> 
> I see what you are saying.  The intent here was to be fairly 
> abstract.  Perhaps I should be more explicit in the example. I
> talk about the food and wine ontologies and use the &vin 
> construct but without explicit reference to &food.  How about
> modifying the second paragraph of 4.1 from
> 
>  One way to do this is by defining a class in the food ontology
>  and ...
> 
> to read
> 
>  One way to do this is by defining a class in the food ontology 
>  (&food;Wine) and ...

Ok.

> > 5) I think the second example in section 5.1.2 deserves
> >    more explanation. Section 5.1.1 is about intersections.
> >    The example in 5.1.2 refers to the "intersection of
> >    sweet and non-sweet fruit," but the intersectionOf
> >    operator that was just introduced is not present. 
> >    I see from section 3.1.1 that "Instances of the class 
> >    belong to the intersection of the restrictions [that
> >    appear in the class definition]." That subtle point is
> >    lost in the wake of 5.1.1. 
> 
> I thought the point was fairly clear.  But I have been staring 
> at this document for a long time.  5.1.1 states that
> 
>  The construction above states that WhiteWine is exactly the
>  intersection of the class Wine and the set of things that are white in
>  color.
> 
> 5.1.2 states
> 
>  This says that the instances of Fruit are a subset of the intersection
>  of sweet and non-sweet fruit, which we would expect to be the empty
>  set.
> 
> >    In fact, would the example in 5.1.2 be better off
> >    in section 5.1.1?
> 
> The reason to pull this example into the unionOf discussion is that 
> some people have misinterpreted the implicit combination of the 
> two subClassOf's.  The other point is that this second example is not 
> definitional, and the text is an explicit reminder to the reader of
> the difference.  As well as the difference between this construct
> and that in 5.1.1. 
>  
> >    Also, the example revealed to me that I do not
> >    understand why rdf:resource is used in some cases
> >    and why rdf:about is used in others. The topic
> >    is introduced in 3.1.1, but I don't get a good
> >    understanding of the difference there. The Guide says
> >    that rdf:about is used to "extend the definition of
> >    a resource." However, I don't see any extensions
> >    going on in the example in 5.1.2. 

> There is some confusion in my text.  The "extend the definition" text
> is meant to differentiate rdf:ID and rdf:about.  And rereading it, I
> don't think that is clear, given how rdf:resource is used in the 
> middle of the text.  I suggest changing:
> 
>  Within this document, the Region class can now be referred to 
>  using rdf:resource="#Region". 
> 
> to 
> 
>  Within this document, the Region class can now be referred to 
>  using #Region, e.g. rdf:resource="#Region". 
> 
> The id/about distinction is that rdf:ID is meant to be used in the
> initial introduction of an element and rdf:about is used to elaborate
> on it in a further description.  

There should be some explanation about why rdf:about is 
*preferable* to rdf:ID. In particular, the TAG's Architecture
Document promotes web-wide linking, and I think rdf:about fits
better than rdf:ID.

Thank you,

 _ Ian

> rdf:resource is used in a property instance, typically to identify 
> the range element.
> 
> -----Original Message-----
> From: Ian B. Jacobs [mailto:ij@w3.org] 
> Sent: Wednesday, October 15, 2003 11:40 PM
> To: public-webont-comments@w3.org
> Cc: ij@w3.org
> Subject: Minor comments on 18 Aug 2003 OWL Guide [attempt 2]
> 
> 
> Hello,
> 
> [I just hit the send button by mistake on an incomplete
>  mail....let's try again...]
> 
> I have just read most of the 18 Aug 2003 draft of 
> the OWL Guide [1], which I found very readable and
> helpful. I have a couple of questions on minor
> editorial points.
> 
> 1) Subsections of 3.4 are numbered; subsections of 3.3
>    are not. I think those of 3.3 should also be
>    <h3> numbered headers.
> 
> 2) Under 3.3, inverseOf, "z" is mentioned in the first
>    sentence (before the colon) but is not used in 
>        P1(x,y) iff P2(y,x)
> 
> 3) Under 3.3, inverseFuntionalProperty, on the other hand,
>    "z" is not used in the first sentence but does appear
>     in 
>        P(y,x) and P(z,x) implies y = z.
> 
>    It looks as though the first sentences were switched...
> 
> 4) The first few paragraphs of section 4 (Ontology mapping)
>    seemed to cry out for at least a mention of namespaces.
>    This comment is not that important, but if there is
>    more information in another document about ontology
>    sharing, a reference to it would be helpful.
> 
> 5) I think the second example in section 5.1.2 deserves
>    more explanation. Section 5.1.1 is about intersections.
>    The example in 5.1.2 refers to the "intersection of
>    sweet and non-sweet fruit," but the intersectionOf
>    operator that was just introduced is not present. 
>    I see from section 3.1.1 that "Instances of the class 
>    belong to the intersection of the restrictions [that
>    appear in the class definition]." That subtle point is
>    lost in the wake of 5.1.1. 
> 
>    In fact, would the example in 5.1.2 be better off
>    in section 5.1.1?
> 
>    Also, the example revealed to me that I do not
>    understand why rdf:resource is used in some cases
>    and why rdf:about is used in others. The topic
>    is introduced in 3.1.1, but I don't get a good
>    understanding of the difference there. The Guide says
>    that rdf:about is used to "extend the definition of
>    a resource." However, I don't see any extensions
>    going on in the example in 5.1.2. 
> 
> Thank you,
> 
>  _ Ian
>     
> [1] http://www.w3.org/TR/2003/CR-owl-guide-20030818/
-- 
Ian Jacobs (ij@w3.org)   http://www.w3.org/People/Jacobs
Tel:                     +1 718 260-9447

Received on Monday, 3 November 2003 08:40:08 GMT

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