W3C home > Mailing lists > Public > public-prov-wg@w3.org > July 2011

Re: PROV-ISSUE-35: Section 4: How one would know that two BOBs are characterizations of the same entity? [Conceptual Model]

From: Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>
Date: Thu, 21 Jul 2011 20:39:52 +0100
Message-ID: <4E288088.2020202@cs.man.ac.uk>
To: Luc Moreau <l.moreau@ecs.soton.ac.uk>
CC: public-prov-wg@w3.org

On 21/07/2011 20:20, Luc Moreau wrote:
>
> Hi Khalid,
> Can you expand on this? What would it help us to achieve?
>
> At F2F1, some mentioned "turtle all way down" to refer to the idea 
> that we are not trying
> to make a distinction between an entity and its state (as we used to 
> say then).
> This would translate into the fact that we only have characterized 
> entities ...
>   and are not trying to distinguish an entity from a characterized 
> entity.
>
> Can you explain what benefits you see in distinguishing entity from 
> characterized entity?
>
> So, does it mean in the example, you would say that e1 is same entity 
> as e2?
> Potentially, this could be captured by (the very rough) definition of 
> version.

Yes, possibly, I actually first thought that "isRevisionOf" can be used, 
but I think it poses stronger condition that what is needed by 
"sameEntity".

Regarding your question about the benefits. I think, having 
"sameEntity()" can be used in the definition of IVPof:
Specifically, in page 10, it is stated that:

"An assertion "B is an IVP of A" holds over the temporal intersection of 
A and B, /only if/:

   1. if a mapping can be established from an attribute X of B to an
      attribute Y of A, then the values of A and B must be consistent
      with that mapping
   2. B has some attribute that A does not have"

I think, if "sameEntity" exists then it can be used as a third 
condition, to make sure that A and B refers to the same entity, 
otherwise one cannot be an IVPof the other.

Also, given a BOB bi, a user  may be interested in tracing the history 
of all the BOBs that were used to derive b1 and that refer to the same 
entity. In other words, the query here is give me the history of the 
entity that bi refers to.

khalid

>
>
> Luc
>
> On 21/07/2011 20:06, Provenance Working Group Issue Tracker wrote:
>> PROV-ISSUE-35: Section 4: How one would know that two BOBs are 
>> characterizations of the same entity? [Conceptual Model]
>>
>> http://www.w3.org/2011/prov/track/issues/35
>>
>> Raised by: Khalid Belhajjame
>> On product: Conceptual Model
>>
>>
>> Do we need a mean to specify that two BOB are characterizations of 
>> the same entity?
>>
>> In the initial draft, I think that the editors intentionally avoided 
>> defining the term "entity" as part of the vocabulary. I don't suggest 
>> defining that term, but having a means by which one would know that 
>> two Bobs are characterizations, possibly different, of the same 
>> entity, e.g., using an assertion like "sameEntity(bob1, bob2)".
>>
>> I think this will be useful, amongst other things, in the definition 
>> of IVPof.
>>
>> Khalid
>>
>>
>>
>
>
Received on Thursday, 21 July 2011 19:40:20 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, 26 April 2012 13:06:37 GMT