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Re: PROV-ISSUE-153 (complementarity): Complementarity description differs from model definition [Primer]

From: Paolo Missier <Paolo.Missier@ncl.ac.uk>
Date: Tue, 22 Nov 2011 07:53:43 +0000
Message-ID: <4ECB5507.1020103@ncl.ac.uk>
To: public-prov-wg@w3.org

well the PROV-DM wording tries to convey precisely what Graham summarizes at the end of his issue:  "the characterizations overlap 
in some sense"
so it is symmetric in the general case, and a-symmetric in the special case where one of the two sets of attributes in included in 
the other.

in this sense, the text in the primer is differerent:
" we say there is/complementarity/between one entity and another if everything that characterizes the second is also true of the first."

can we somehow restore this idea of partial mutual overlap?

Thanks, -Paolo

On 11/21/11 9:10 PM, Simon Miles wrote:
> Hello Graham,
> I don't think either the complementarity concept in Prov-DM or the
> wasComplementOf relation in Prov-O are symmetric are they? The Prov-DM
> description of complementarity specifically includes "In the
> particular case where the set P of attributes of B is a strict
> superset of A's attributes, then we say that B is-complement-of A, but
> in this case the opposite does not hold." If complementarity is
> asymmetric in any case, then it is an asymmetric relation in general.
> The Prov-O wasComplementOf relation has a direction and it isn't said
> to imply the inverse.
> More importantly, the primer intuition section should not try to cover
> all the possible cases or make normative statements, but illuminate
> the key idea with a simple example. I believe the key idea of
> complementarity is that two entities may be perspectives on the same
> thing, and I think the first paragraph does describe this key idea.
> The second paragraph in the primer is then a more detailed example,
> using the asymmetric case. I agree that complementarity is not
> necessarily asymmetric, but I think that case is the easiest to
> briefly explain why prov:wasComplementOf has direction in the worked
> example.
> I'm open to suggestions on how to be clearer and more complete in this
> section as long as we keep it non-technical.
> Thanks,
> Simon
> On 18 November 2011 09:17, Provenance Working Group Issue Tracker
> <sysbot+tracker@w3.org>  wrote:
>> PROV-ISSUE-153 (complementarity): Complementarity description differs from model definition [Primer]
>> http://www.w3.org/2011/prov/track/issues/153
>> Raised by: Graham Klyne
>> On product: Primer
>> Primer section: 2.7 Complementarity
>> While I personally think the notion of complementarity described here is the
>> more useful one, I don't think it agrees with the current PROV-DM
>> (http://dvcs.w3.org/hg/prov/raw-file/tip/model/ProvenanceModel.html#record-complement-of).
>> (What you describe here might be termed "characterizationOf" (of "viewOf"),
>> which notion I see as being foundational to the way entities are related to
>> things.)
>> To clarify: in my reading, primer defines complementarity as an asymmetric relationship, where one characterization is subsumed by the other.  But the model definition is symmetric,  simply saying that the characterizations overlap in some sense.

-----------  ~oo~  --------------
Paolo Missier - Paolo.Missier@newcastle.ac.uk, pmissier@acm.org
School of Computing Science, Newcastle University,  UK
Received on Tuesday, 22 November 2011 07:54:15 UTC

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