RE: specializationOf and inference

> In Prov, prov:Entities stand for aspects/views of things, not the things themselves.  

Is that always the case, or only when there are alternateOf of specializationOf relationships involved? 
In prov-o the definition of Entity is 

"An entity is a physical, digital, conceptual, or other kind of thing with some fixed aspects; entities may be real or imaginary." 

This appears to say that Entity can be the thing itself. 

Simon Cox

 
From: James Cheney
Sent: 26 July 2017 18:01
To: Pierre-Antoine Champin
Cc: public-prov-comments@w3.org; Stian Soiland-Reyes
Subject: Re: specializationOf and inference
 
Hi Pierre, 
 
In Prov, prov:Entities stand for aspects/views of things, not the things themselves.  
 
In your example, <#me> is a more general prov:Entity representing a person's whole existence and <#me-today> is a more specific one representing a part of that existence, so in particular we can infer <#me-today> :ssn "123456789" from <#me> :ssn "123456789".  You assert that :ssn is inverse functional, which means that since the two URIs have the same predicate value, then they are equal (owl:sameAs).  But this is much stronger than you want: it amounts to saying that the entity <#me> - presumably corresponding to a person's whole existence/timeline - is the same as <#me-today> which only refers to one day of that person's existence.
 
I think in PROV terms, what would work instead is the weaker constraint that if two URIs have the same :ssn then they are prov:alternateOf each other; this says that the two URIs are aspects/views of the same thing but not that they are the same aspects/views of that thing.  
 
Hope that makes some sense,
--James
 
On Jul 26, 2017, at 5:37 PM, Stian Soiland-Reyes <soiland-reyes@manchester.ac.uk> wrote:
 
Thanks for your comments!
 
BTW - in PROV-DM the attributes of entities do *not* include the PROV relations, so the prov:specializationOf (and other PROV relations) are not directly inherited. (The whole purpose of specialization is to provide alternate histories or timelines of a thing)
 
In a way just the attributes “describing” the entity are inherited. So I think your N3 rule is a bit too simple.
 
 
If you include OWL functional properties as part of these attributes, then you are combining two semantic schemes, mixing PROV Constraints and OWL.  I think the ‘easy’ way out here is to then use only OWL2 semantics – which in PROV-O do not imply anything from  prov:specializationOf on OWL level (beyond domain/range prov:Entity  and subproperty of prov:alternateOf).
 
 
We did have a think about expressing the PROV Constraints in OWL – but wanted to keep that as an optional extra so it was not added to PROV-O and some of the constraints could be non-trivial in OWL2. Contributions welcome!
 
If you want to do a richer semantics integration of PROV Constraints and OWL then you have to ensure any OWL-reasoned “sameness” don’t leak over. 
 
-- 
Stian Soiland-Reyes, eScience Lab
School of Computer Science, The University of Manchester
http://orcid.org/0000-0001-9842-9718

 
From: Pierre-Antoine Champin
Sent: 26 July 2017 15:35
To: public-prov-comments@w3.org
Subject: specializationOf and inference
 
Hi all,
I'm currently interested in using prov:specializationOf, as it seems to provide a weaker (and hence more flexible) "sameness" as owl:sameAs. Indeed, the "specializer" inherits the properties of the "specializee", but not the other way around (as would be the case for owl:sameAs).
More precisely, I interpret inference rule 21 [1] as the following N3 rule:

   { ?x1 prov:specializationOf ?x2. ?x2 ?p ?o } => { ?x1 ?p ?o }
So, from
  <#me-today> prov:specializationOf <#me> .
  <#me-today> :mood :happy.
  <#me> foaf:name "Pierre-Antoine".
I could infer

  <#me-today> foaf:name "Pierre-Antoine".
That's very well. But now, assume that I have
  :ssn a owl:InverseFunctionalProperty .
  <#me> :ssn "123456789".
Similarly, I would also infer

  <#me-today> :ssn "123456789".
But this would also lead me to infer
 
  <#me> owl:sameAs <#me-today>.
which is precisely why I wanted to avoid :-(
What is wrong in my reasoning?
 
[1] https://www.w3.org/TR/2013/REC-prov-constraints-20130430/#specialization-attributes-inference

Received on Friday, 28 July 2017 04:07:06 UTC