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Re: PROV-ISSUE-29 (mutual-iVP-of): can two bobs be mutually "IVP of" each other [Conceptual Model]

From: James Cheney <jcheney@inf.ed.ac.uk>
Date: Tue, 27 Mar 2012 22:42:31 +0300
Cc: Jim McCusker <mccusj@rpi.edu>, public-prov-wg@w3.org
Message-Id: <F79C1B44-3D98-469A-AD0B-DF9E8CF84404@inf.ed.ac.uk>
To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
('binary' encoding is not supported, stored as-is)
Hi,

The formal semantics draft for WD3 [1] addressed this, and the bottom line is currently:

alternateOf: reflexive, symmetric, NOT transitive (due to the requirement that entity intervals overlap).

specializationOf: reflexive, transitive, NOT symmetric, NOT antisymmetric (no requirement that two mutually specializing entities are equal, but we could add this).

We can easily adjust the formalization of specializationOf to not be reflexive (or to require that it is irreflexive).

I plan to read the current version of WD5 over the next day or so and update this.  I don't think the informal definitions have changed that much though.

Part of the point of the formal semantics is to provide a rationalization for these types of properties, especially where there has been a lot of discussion or disagreement.  So I would appreciate feedback on the formal semantics from people who are interested in these questions.  I will also notify the list by Friday when the revised version is ready.  (At a conference this week so it's been hard to find time for this since my talk was today.)

--James

[1] http://www.w3.org/2011/prov/wiki/FormalSemanticsWD3

On Mar 27, 2012, at 7:28 PM, Luc Moreau wrote:

> Hi Jim,
> 
> Agreed, we could be silent about reflexivity, which means we don't say whether specializationOf is
> reflexive or irreflexive.
> 
> That's a conservative position, I am fine with.
> 
> 
> The English definition uses the term 'more constrained' which is probably too vague to decide one or the other.
> 
>  An entity is a specialization of another if they both refer to some common thing
>  but the former is a more constrained entity than the former. The common entity does not need to be identified.
> 
> 
> Luc
> 
> 
> On 03/27/2012 05:20 PM, Jim McCusker wrote:
>> 
>> I'm not sure if it is or not. I'm willing to support proposals as to why it might be, but I haven't seen any good arguments for it yet. Even if we think it might be, we may want to hold off on declaring it.    
>> 
>> Neither rdfs:subClassOf or skos:broader are reflexive, and I think the same arguments apply to making them reflexive. People who are interested in having a reflexive specializationOf could make a subproperty (if it's domain specific) or superproperty (if they think that it always holds), depending on their needs. However, if we define it to be reflexive ourselves, we complicate matters for those who think that it isn't.
>> 
>> Jim
>> 
>> On Tue, Mar 27, 2012 at 12:09 PM, Luc Moreau <L.Moreau@ecs.soton.ac.uk> wrote:
>> Hi,
>> As we discuss axioms of specialization/alternateOf
>> 
>> is specializationOf  reflexive?
>> 
>> Luc
>> 
>> 
>> On 03/27/2012 03:52 PM, Stian Soiland-Reyes wrote:
>> alt1 and alt2 is good. It is fairly obvious (but should be explained
>> in constraints) that alternateOf(a, b) indirectly implies
>> alternateOf(b, a), as it implies
>> 
>> specializationOf(a, X)
>> specializationOf(b, X)
>> 
>> and that implies:
>> 
>> alternateOf(b, a)
>> alternateOf(a, b)
>> 
>> 
>> Would we need to say that if
>> 
>>   alternateOf(a, b)
>>   alternateOf(a, c)
>> 
>> it does not imply:
>> 
>>   alternateOf(b, c)
>> 
>> ?
>> 
>> 
>> On Mon, Mar 26, 2012 at 22:46, Jim McCusker<mccusj@rpi.edu>  wrote:
>>   
>> Do they need fully contextualized names? Can they just be a and b, or x and
>> y? I'm pretty sure this isn't a qualified relation...
>> 
>> Jim
>> 
>> 
>> On Mon, Mar 26, 2012 at 5:41 PM, Luc Moreau<L.Moreau@ecs.soton.ac.uk>
>> wrote:
>>     
>> 
>> BTW, has somebody got better names for first and second alternate?
>> 
>> 
>> http://dvcs.w3.org/hg/prov/raw-file/default/model/working-copy/wd5-prov-dm-alternate.html#alternate.firstAlternate
>> 
>> http://dvcs.w3.org/hg/prov/raw-file/default/model/working-copy/wd5-prov-dm-alternate.html#alternate.secondAlternate
>> 
>> Thanks,
>> Luc
>> 
>> 
>> On 26/03/12 22:38, Luc Moreau wrote:
>> 
>> Hi Paolo,
>> 
>> I have updated the text to make it clear that the common entity does not
>> need
>> to be identified.
>> 
>> http://dvcs.w3.org/hg/prov/rev/21b96bf05727
>> 
>> Cheers,
>> Luc
>> 
>> On 26/03/12 15:59, Paolo Missier wrote:
>> 
>> Luc
>> 
>> 
>> On 3/26/12 2:54 PM, Luc Moreau wrote:
>> 
>> Dear all,
>> 
>> Thanks for your very useful suggestions.
>> 
>> I have drafted a revised section in a separate file
>> 
>> http://dvcs.w3.org/hg/prov/raw-file/default/model/working-copy/wd5-prov-dm-alternate.html
>> 
>> Does capture what has been discussed so far?
>> 
>> I think so. To me it is important that when we say
>> " They are both specialization of an (unspecified) entity." eg in the
>> first example, it is clear that there no obligation to say anything about
>> the common entity that they specialize. This, however, contrasts with the
>> definition itself:
>> " An entity is alternate of another if they are both a specialization of
>> some common entity."
>> It is not clear what to make of this defining property of alternates -- it
>> gives an existential condition which is not actionable in general. So to me
>> this is potentially confusing.
>> 
>> 
>> Also, if specialization(a,b) is it the case that alternateOf(a,b)?
>> 
>> no. I recall that we've been there before. At some point there was a
>> discussion on specialization having a "top" and being transitive and
>> therefore, with this additional inferences, everything would collapse.
>> 
>> Regards,
>>   -Paolo
>> 
>> 
>> Regards,
>> Luc
>> 
>> On 25/03/2012 17:16, Timothy Lebo wrote:
>> 
>> 
>> On Mar 25, 2012, at 9:43 AM, Jim McCusker wrote:
>> 
>> On Sun, Mar 25, 2012 at 3:18 AM, Graham Klyne<GK@ninebynine.org>  wrote:
>>       
>> In my review comments which I think you have yet to get round to, I
>> question whether we actually need to have these concepts in the DM.
>> 
>> Originally, by my recollection, they were introduced to explain the
>> relationship between provenance entities and (possibly dynamic) real world
>> things.  With the looser description of the provenance model terms, I don't
>> see why this level of detail is needed in the data model.
>>         
>> 
>> Then you don't recollect correctly.
>> 
>> 
>> I remember IPV-of as the "relationship between provenance entities and
>> (possibly dynamic) real world things", but specializationOf has developed
>> into a more general association between entities that can include this
>> original purpose. Indeed, eg-19 [1] is using alt and specOf for _exactly_
>> this original "frozen snapshot of changing things" notion -- applied to
>> datasets and web services.
>> 
>> Instead of digging up the archives, perhaps we can rally around altOf and
>> specOf being the tools we use to associate (and make sense of) assertions
>> made by the combinations of scruffy and proper provenance.
>> (Like Simon's extension to Stian's BBC example). In addition, it's an
>> incredibly useful construct for one's own "proper" modeling.
>> 
>> [1] http://www.w3.org/2011/prov/wiki/Eg-19-derived-named-graph-attribution
>> 
>> They were defined because there was an acknowledgement that there were
>> multiple symbols that denoted a common thing in the world. Sometimes they
>> reflected different aspects of the same thing (alternativeOf) and sometimes
>> they had a subsumptive quality (specializationOf).
>> 
>> 
>> I think these previous two statements contradict (and steer scarily
>> towards owl:sameAs, which alt and specOf are certainly _not_)
>> Different aspects of the same thing are not the same things.
>> 
>> -Tim
>> 
>> 
>> Jim
>> --
>> Jim McCusker
>> Programmer Analyst
>> Krauthammer Lab, Pathology Informatics
>> Yale School of Medicine
>> james.mccusker@yale.edu | (203) 785-6330
>> http://krauthammerlab.med.yale.edu
>> 
>> PhD Student
>> Tetherless World Constellation
>> Rensselaer Polytechnic Institute
>> mccusj@cs.rpi.edu
>> http://tw.rpi.edu
>> 
>> 
>> 
>> 
>> --
>> -----------  ~oo~  --------------
>> Paolo Missier - Paolo.Missier@newcastle.ac.uk, pmissier@acm.org
>> School of Computing Science, Newcastle University,  UK
>> http://www.cs.ncl.ac.uk/people/Paolo.Missier
>> 
>>       
>> 
>> 
>> 
>> --
>> Jim McCusker
>> Programmer Analyst
>> Krauthammer Lab, Pathology Informatics
>> Yale School of Medicine
>> james.mccusker@yale.edu | (203) 785-6330
>> http://krauthammerlab.med.yale.edu
>> 
>> PhD Student
>> Tetherless World Constellation
>> Rensselaer Polytechnic Institute
>> mccusj@cs.rpi.edu
>> http://tw.rpi.edu
>>     
>> 
>> 
>>   
>> 
>> -- 
>> Professor Luc Moreau
>> Electronics and Computer Science   tel:   +44 23 8059 4487
>> University of Southampton          fax:   +44 23 8059 2865
>> Southampton SO17 1BJ               email: l.moreau@ecs.soton.ac.uk
>> United Kingdom                     http://www.ecs.soton.ac.uk/~lavm
>> 
>> 
>> 
>> 
>> 
>> -- 
>> Jim McCusker
>> Programmer Analyst
>> Krauthammer Lab, Pathology Informatics
>> Yale School of Medicine
>> james.mccusker@yale.edu | (203) 785-6330
>> http://krauthammerlab.med.yale.edu
>> 
>> PhD Student
>> Tetherless World Constellation
>> Rensselaer Polytechnic Institute
>> mccusj@cs.rpi.edu
>> http://tw.rpi.edu
> 
> -- 
> Professor Luc Moreau               
> Electronics and Computer Science   tel:   +44 23 8059 4487         
> University of Southampton          fax:   +44 23 8059 2865         
> Southampton SO17 1BJ               email: l.moreau@ecs.soton.ac.uk  
> United Kingdom                     http://www.ecs.soton.ac.uk/~lavm



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Received on Tuesday, 27 March 2012 19:43:16 GMT

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