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

From: Graham Klyne <GK@ninebynine.org>
Date: Wed, 23 Nov 2011 09:18:04 +0000
Message-ID: <4ECCBA4C.5060403@ninebynine.org>
To: Paolo Missier <Paolo.Missier@ncl.ac.uk>
CC: public-prov-wg@w3.org
Paolo,

On 23/11/2011 08:24, Paolo Missier wrote:
> Graham, Jim
>
> -1 for the use of the term "contextualized".
> You are using "context" to denote inclusion amongst the set of attributes that
> characterise two entities. Context has many meanings but it is not a term that
> springs to mind when I see set inclusion (I would be more likely to think of
> "restriction").

"restricts" maybe could work for me.

> -1 for using "contextualized" as the basis for "complementarity".
> as Graham points out:
>
> A1 \subset B and A1 \subset B does not imply that A1 and A2 are not disjoint.

Out of interest, do you have a use-case for which complementarity depends on 
there being an actual overlap of attributes, as opposed to both being 
contextualizations of some common thing?

(Arguably, in an open-world environment such as the web, the fact that two 
entities contextualize some common other entity suggests very strongly that 
there does exist some attribute that is common, even if it has not been explicated.)

#g
--


> On 11/22/11 9:56 PM, Graham Klyne wrote:
>> On 22/11/2011 15:46, Jim McCusker wrote:
>>> +1 to GK's identification of (there is X between one entity and another if
>>> everything that characterizes the second is also true of the first) as a
>>> useful property. I propose "contextualized" as the predicate. Two entities
>>> that contextualized a common entity complemented (in our current parlance)
>>> each other.
>
>> Yes, but a nit: I think it's possible for:
>>
>> A1 contextualized A
>> A2 contextualized A
>>
>> without:
>>
>> A1 complemented A2
>>
>> as it is, by my understanding, possible for A1 and A2 to have no overlapping
>> attributes. (Like: http://www.jainworld.com/literature/story25.htm ?)
>>
>> (But, personally, I think I prefer this definition, which isn't possible without
>> the "contextualized" notion.)
>>
>>> Also, I like "contextualized" and "complemented" as terms here rather than
>>> "wasContextualizationOf" and "wasComplementOf" since it's a clearer verb
>>> phrase, easier to remember, shorter, and more direct.
>> I think I could come to like that :)
>>
>> #g
>> --
>>
>>> On Tue, Nov 22, 2011 at 6:46 AM, Graham Klyne<GK@ninebynine.org> wrote:
>>>
>>>> Simon,
>>>>
>>>> (hurried response)
>>>>
>>>> I think what you say is True. But Primer says (or said):
>>>>
>>>> [[
>>>> In PROV-DM, we say there is complementarity between one entity and another
>>>> if everything that characterizes the second is also true of the first.
>>>> ]]
>>>> --
>>>> http://dvcs.w3.org/hg/prov/**raw-file/4ebbb4e5ca48/primer/**
>>>> Primer.html#complementarity<http://dvcs.w3.org/hg/prov/raw-file/4ebbb4e5ca48/primer/Primer.html#complementarity>
>>>>
>>>>
>>>> My point was that this is not aligned with PROV-DM.
>>>>
>>>> But I happen to think it's a more useful property to define (modulo name)
>>>> - and as stated above is clearly transitive.
>>>>
>>>> #g
>>>> --
>>>>
>>>>
>>>> On 21/11/2011 21:10, 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<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<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.
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>
>
Received on Wednesday, 23 November 2011 09:19:17 UTC

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