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Re: [SKOS] Comments on SKOS Primer - other points

From: Thomas Baker <baker@sub.uni-goettingen.de>
Date: Thu, 8 Jan 2009 18:22:33 +0100
To: Thomas Baker <baker@sub.uni-goettingen.de>
Cc: Antoine Isaac <aisaac@few.vu.nl>, SWD Working Group <public-swd-wg@w3.org>
Message-ID: <20090108172233.GA3080@octavius>

Antoine and Ed,

The remaining points...

On Wed, Jan 07, 2009 at 06:28:39PM +0100, Thomas Baker wrote:
> > >-- I find the following sentence in Section 3.2 to be unclear:
> > >
> > >    For example, a SKOS publisher can choose to locally extend
> > >    an existing concept scheme, and then publish the extension
> > >    with the linkages intact.
> > >  
> > >   What does "publish the extension" mean, and what "linkages"
> > >   are remaining intact?
> > 
> > We had a different formulation before, but it was even worse :-( I'd 
> > propose to replace by [[
> > For example, a SKOS publisher can choose to locally extend an existing 
> > concept scheme. In that case, the set of new concepts can just be published 
> > alone, linking to the concepts in the already existing scheme rather than 
> > re-defining them.
> > ]]
> > @@TODO@@
> 
> That's much better but could perhaps be further improved; I'll 
> think about it too.

Do you want to say:

    For example, a SKOS publisher can choose to locally extend
    an existing concept scheme by declaring any new concepts
    that may be needed and simply linking to concepts that
    have already been defined in the existing scheme.

> > >-- The second sentence in the following is not very clear (and is not
> > >   a complete sentence):
> > >
> > >        By convention, mapping relationships are also expected
> > >        to be asserted between concepts that belong to
> > >        different concept schemes. Although specific scenarios
> > >        (such as enriching a concept scheme that lacks desired
> > >        semantic structure) may sometimes necessitate create
> > >        mappings within a scheme.
> > >
> > >   If mappings within a scheme were needed, one would normally use semantic
> > >   relation properties.  Is the point here that one might want to enrich
> > >   _somebody else's_ concept scheme?
> > 
> > Yes. Would you want that to be explicitly written?
> 
> I'll think about this too.

Instead of:

      <p>By convention, mapping properties are used to represent links that have
      the same intended meaning as the "standard" semantic properties, but with a
      different scope. One might say that mapping relationships are less
      <em>inherent</em> to the meaning of the concepts they involve. From the point
      of view of the original designer of a mapped KOS, they might even sometimes
      be wrong. Mapping properties are expected to be useful in <em>specific</em>
      applications that use multiple, conceptually overlapping KOSs.</p>
      
      <p>Instead, their motivation is expected to be tightly related to a specific
      application that requires them to cope, say, with conceptual redundancy
      resulting from several KOSs coexisting.</p>
      
      <p>By convention, mapping relationships are also expected to be asserted
      between concepts that belong to different concept schemes. Although specific
      scenarios (such as enriching a concept scheme that lacks desired semantic
      structure) may sometimes necessitate create mappings within a scheme.</p>
      
      <p>Finally, the reader should be aware that according to the SKOS data model,
      the mapping properties that "mirror" a given semantic relation property are
      also sub-properties of it in the RDFS sense. For instance,
      <code>skos:broadMatch</code> is a sub-property of <code>skos:broader</code>.
      Consequently, every assertion of <code>skos:broadMatch</code> between two
      concepts leads by inference to asserting a <code>skos:broader</code> between
      these concepts. With concept scheme extension discussed in the following
      section, this is one of the situations where the SKOS basic semantic
      relationships defined in Section 2.2 can hold across different concept
      schemes.</p>

I suggest:

      <p>By convention, mapping properties are used to represent
      links that have the same intended meaning as the "standard"
      semantic properties, but with a different scope. One might
      say that mapping relationships are less <em>inherent</em>
      to the meaning of the concepts they involve. From the point
      of view of the original designer of a mapped KOS, they might
      even sometimes be wrong.</p>
      
      <p>Mapping properties are expected to be useful
      in <em>specific</em> applications that use multiple,
      conceptually overlapping KOSs.  By convention, mapping
      relationships are expected to be asserted between concepts
      that belong to different concept schemes.  However, the use of
      mapping properties might also be appropriate in cases where
      someone other than its owner needs to enrich the semantic
      relationships within a particular concept scheme.</p>
      
      <p>The reader should be aware that according to the SKOS
      data model, the mapping properties that "mirror" a given
      semantic relation property are also sub-properties of it in
      the RDFS sense. For instance, <code>skos:broadMatch</code> is a
      sub-property of <code>skos:broader</code>.  Consequently, every
      assertion of <code>skos:broadMatch</code> between two concepts
      leads by inference to asserting a <code>skos:broader</code>
      between these concepts.</p> <hr>

In other words:

-- Suggest dropping the final sentence in the last paragraph, 
   which I understand but do not know why it needs to be said
   (and therefore find confusing).  I do not at any rate think
   it is needed here as a transition sentence.

-- Suggest dropping the one-sentence second paragraph, as the 
   preceding sentence ("conceptually overlapping") already makes
   the point.

In addition, I suggest:

995c995
< <code>ex2:eggSellerScheme</code> using the mapping assertions below:</p>
---
> <code>ex2:eggSellerScheme</code> by using the mapping assertions below:</p>

It is not the _concept_ that is using the mapping assertion, as a sleepy
reader might at first conclude.

1001,1002c1001,1002
< sufficiently similar that they can be used interchangeably in applications
< that consider the two concept schemes they belong to. However,
---
> sufficiently similar that they can be used interchangeably in applications.
> However,

Here, the deleted words seem redundant.

Tom

-- 
Tom Baker <tbaker@tbaker.de>
Received on Thursday, 8 January 2009 17:23:19 GMT

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