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Re: Is _this_ what is meant by "Entity"?

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Mon, 05 Sep 2011 08:13:35 +0100
Message-ID: <EMEW3|994adc0a73daf93b7a9016142b8efd62n848Df08L.Moreau|ecs.soton.ac.uk|4E64769F.7070506@ecs.soton.ac.uk>
To: public-prov-wg@w3.org
Hi Jim,

Your notion of entity differs slightly to the one in the current model 
document.

You tend to define the invariance of an entity with respect to processes 
it participates
in.  The current document tends to refer to characterization interval 
(which needs
to be better explained, I agree).

I personally prefer the latter approach, since it allows us to define 
entity independently
of participation/process execution.  I believe however that a 
consequence of this definition,
is the invariance of entities with respect to PE they participate in.

Cheers,
Luc


PS. ISSUE-85

On 09/03/2011 04:57 PM, Myers, Jim wrote:
> Jim
>   - I'm see no difference between what you and Graham expressed, but I
> guess you want to ensure he didn't mean:
>    a. "e0 is a file THAT HAPPENS AT THE MOMENT TO be at file system
> location is /shared/crime.txt and which have been created by Alice"
>    b. "e0 is COMPLETELY DEFINED BY BEING (not just a perspective on) a
> file at /shared/crime.txt created by Alice"
> Right?
>
> --- ~Yes. Thinking of e0 as the file with some annotations on it doesn't seem deep enough to me - e0 is what a file would be in a theory where file objects can't move. Because e0 defines its behavior relative to certain processes of interest, it is different than a thing for which behavior hasn't been specified- it has a time/process dimension that a thing doesn't necessarily have (some things - like a resource identified by a persistent/cool URL already embed some notion of time and allowed processes (and they are entities/it is valid to assert that they are entities)- which is where some of the confusion between entity and thing might arise.) (Conversely, some entities - me defined to be the set of atoms in my body - have a rather strange evolution (I spread out over the planet over time...) and while I think I could define a web resource to represent that theory of me, I doubt one would ever find such a thing in the wild...)
>
>   - Your example of overwriting a file in a single location nicely
> illustrates nuances of the entity definition, and I guess we need
> something of this sort in the primer. Though we might have to explain
> things simply but not completely correctly before getting to accurate
> but challenging :-)
>
>   - I find your definition of entity more opaque than the current one
> (sorry). What is an "asserted interpretation"?
>
> --- Ah well... Somehow I'm trying to get the sense in my comment above - entity forces you to define a theory for how a thing behaves relative to processes of interest. You have to nail down how your notion of identity for whatever you're talking about is affected by relevant processes (When I talk about files, I consider two files to be different if their content is different, therefore content is a fixed attribute in my theory of the world and I can unabigously tell you about a given files provenance in terms of any editing processes that created it).
>
> That may not help either...
>
> Cheers,
>   Jim
>    

-- 
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
Received on Monday, 5 September 2011 07:14:05 GMT

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