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

From: Thomas Baker <baker@sub.uni-goettingen.de>
Date: Fri, 9 Jan 2009 14:50:56 +0100
To: Antoine Isaac <aisaac@few.vu.nl>
Cc: Alistair Miles <alistair.miles@zoo.ox.ac.uk>, Thomas Baker <baker@sub.uni-goettingen.de>, SWD Working Group <public-swd-wg@w3.org>
Message-ID: <20090109135056.GA3136@octavius>

On Thu, Jan 08, 2009 at 08:01:43PM +0100, Antoine Isaac wrote:
> >>      <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>
> >I like Tom's wording here.
> >
> >In fact, I would be tempted drop the first of these three paragraphs
> >altogether. If I had no prior knowledge of SKOS, I would find the
> >first two sentences ambiguous. The words "scope" and "inherent" are
> >particularly difficult here. 
> I can understand this. Would s/scope/application scope improve the 
> situation? 
> >And I'm not sure what value the third
> >sentence adds. I.e. one hopes that cases where the KOS designer and
> >the KOS mapper completely disagree about the nature of a mapping link
> >would be very rare. A brief, casual mention such as this may leave the
> >wrong impression, e.g. that these cases could be quite frequent.
> In fact I expect that these cases would be quite frequent. If a KOS 
> designer agreed that a mapping link between two concepts in her KOS fit her 
> intent when creating the KOS, she would have created it as a standard 
> semantic relationship then, wouldn't she?

Well, maybe the project ended, or she simply overlooked the
relationships or just ran out of time...  The point is here
perhaps not so much about agreement or disagreement.

Given the sub-property relationship between "mapping" and
"standard" relationships, we are characterizing the difference
between the two as being "conventional" in nature.

What is the essence of that convention?  I think of a
"standard" relationship as asserting "A skos:broader B",
where the corresponding "mapping" relationship would assert
something like: "I'm not the owner or designer of the concept
scheme, but A skos:broader B".

Maybe it's like being on a "tu" or "vous" basis with
the concept scheme -- a cultural distinction that sends
signals without altering the basic (second-person-singular)
relationship :-)

The argument could run as follows: Ideally, we should be able
to tell from provenance information who said what, but in
practice, Semantic Web data is often merged in simple ways that
obscure the origins of assertions.  The distinction between
"mapping" and "standard" relationships is one of etiquette --
directly asserting "standard" relationships sends the message
that the asserter considers herself qualified to define the
relationship in a standard way.  For everyone else, the polite
thing is to assert a "mapping" relationship.

So I'd be inclined to replace the first paragraph with
something else but would first like to hear whether we agree
on this way to characterize the distinction.


Tom Baker <tbaker@tbaker.de>
Received on Friday, 9 January 2009 13:51:37 UTC

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