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RE: Interpretation of SKOS-Mapping properties ...

From: Danny Ayers <danny666@virgilio.it>
Date: Tue, 2 Dec 2003 10:29:21 +0100
To: <public-esw-thes@w3.org>
Message-ID: <BKELLDAGKABIOCHDFDBPOECHEKAA.danny666@virgilio.it>

Hi Alistair, folks,

I think Steve's got a good point - using the exact figure 50% in the
definitions could mislead people into thinking it had more significance than
an expression of the mappers belief. I'd suggest a minor change to the
wording, from:

> > Instructions to mapper:
> > Use <soks:majorMatch> to link concepts A and B if they overlap
> in meaning,
> > and if you believe that more than 50% of the documents that are about
> > concept A will also be about concept B.

to something like

"...if you believe that the majority of the documents..."

Generally developments are looking great to me - that was quite a flurry of
activity!

The combination constructs are interesting. I've not had a chance to play
yet, but I'd be a little concerned that they seem to be extending the
semantics beyond RDF, and that there might be a clash/incompatibility with
OWL constructs. Any particular reason for not using OWL, btw?

Cheers,
Danny



> -----Original Message-----
> From: public-esw-thes-request@w3.org
> [mailto:public-esw-thes-request@w3.org]On Behalf Of Steve Cayzer
> Sent: 01 December 2003 15:13
> To: public-esw-thes@w3.org
> Cc: public-esw-thes@w3.org
> Subject: Re: Interpretation of SKOS-Mapping properties ...
>
>
>
> Hmmm, I see what you're saying, but I don't see why ">50%" (with its
> illusion of precision) is better than "good" or some such (with its
> guarantee of vagueness).
> What we are talking about here the formal encoding of imprecision :)
>
> Cheers
>
> Steve
> ----- Original Message -----
> From: "Miles, AJ (Alistair) " <A.J.Miles@rl.ac.uk>
> To: "'Steve Cayzer'" <steve.cayzer@hp.com>
> Cc: <public-esw-thes@w3.org>
> Sent: Monday, December 01, 2003 12:16 PM
> Subject: Interpretation of SKOS-Mapping properties ...
>
>
> > Hi Steve,
> >
> > > 3).
> > > The major thing I wanted to post to the list is this (but you
> > > may be able to
> > > answer it directly?)
> > > I notice that on
> > > http://www.w3c.rl.ac.uk/2003/11/21-skos-mapping
> > > has the following properties:
> > >
> > > <rdf:Property rdf:ID="majorMatch">
> > > <rdfs:comment>If 'concept A has-major-match concept B' then the set of
> > > resources properly indexed against concept A shares more than
> > > 50% of its
> > > members with the set of resources properly indexed against concept
> > > B.</rdfs:comment>
> > > </rdf:Property>
> > >
> > > <rdf:Property rdf:ID="minorMatch">
> > >   <rdfs:comment>If 'concept A has-minor-match concept B' then
> > > the set of
> > > resources properly indexed against concept A shares less than 50% but
> > > greater than 0 of its members with the set of resources
> > > properly indexed
> > > against concept B.</rdfs:comment>
> > >     </rdf:Property>
> > >
> > > The use of some number (50%) rings warning bells in my mind.
> > > What about
> > > 49.7% vs 50.1% ? How do we know anyway?
> > > A more comfortable definition (in my mind) would be something vaguer
> > > major match -> This means that a resource properly indexed
> > > against A has a
> > > good chance of being properly indexed against B
> > > minor match -> This means that a resource properly indexed
> > > against A has
> > > some chance of being (or 'may be') properly indexed against B
> >
> > Good point.  This brings up a duality of perspective that I've
> been trying
> > to understand for a while.  Let's have a crack at explaining it...
> >
> > I have defined these properties with formal entailments, i.e. majorMatch
> > entails >50% overlap of the document sets corresponding to the concepts.
> > However, a person creating the mapping must make a best guess as to
> whether
> > this will be true, based on their interpretation of the
> different meanings
> > of the concepts.
> >
> > To make this point another way, consider the following two sets of
> > instructions on how to use the <soks:majorMatch> property, one
> to a person
> > creating a mapping, and one to a programmer developing applications that
> use
> > the <soks:majorMatch> property ...
> >
> > Instructions to mapper:
> > Use <soks:majorMatch> to link concepts A and B if they overlap
> in meaning,
> > and if you believe that more than 50% of the documents that are about
> > concept A will also be about concept B.
> >
> > Instructions to programmer:
> > The ( <ConceptA> <soks:majorMatch> <ConceptB> ) statement entails that
> >50%
> > of the documents properly indexed against concept A are also properly
> > indexed against concept B.  Thus in a query the two concepts may be
> > interchanged, and a success rate of >50% may be expected.
> >
> > I.e. the mapper makes a best guess based on the meaning of the concepts,
> > with imperfect knowledge of the actual document sets, and the programmer
> > writes programs that process these statements as if they are true
> statements
> > about the world, made by someone with perfect knowledge of the document
> > sets.
> >
> > I think it's worth bearing in mind what actual impact these different
> > mapping statements will have to the user.  A good mapping will
> mean that a
> > query app processing transformed queries can guarantee complete recall,
> and
> > order the result set to put better matches first.  A poor mapping means
> lots
> > of bogus results, incomplete recall and no good ordering.  In order to
> > generate a good mapping, the mapper needs the right tools (i.e. a well
> > designed vocab) and must know how to use them (i.e. needs a clear set of
> > instructions).  So this is what we're working towards.
> >
> > How does that go down?
> >
> > Al.
> >
>
Received on Tuesday, 2 December 2003 04:37:31 GMT

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