Re: Some thoughts about the revised provenance Model document

Hi Graham,

Given that we have introduced 'entity expression', you are right that it 
now becomes
possible to talk about 'entity' . As Simon said a while back, 'entity' 
can be defined as 'a characterized thing'.

It will simplify the writing as well.
If there is support for this proposal, we should go ahead, and implement it.

Just a question: do we say the 'entity' is identified by the id? or do 
we say the id denotes the entity?
or do we regard both statements as equivalent in this context?

Cheers,
Luc

On 09/29/2011 11:31 AM, Graham Klyne wrote:
> 1. Terminology: Characterized things, Entities and Entity expressions
>
> The terminology and explanation of these concepts is now much clearer 
> to me.
>
> Referring to the document at 
> http://dvcs.w3.org/hg/prov/raw-file/tip/model/ProvenanceModel.html (as 
> retrieved on 2001-09-29) I note that
> - Fragment #a-conceptualization-of-the-world describes the notions of 
> "things in the world" and "characterized thing"
> - Fragment #prov-dm-overview has a diagram with a box labelled 
> "Entity", which to my mind corresponds to the "characterized thing" 
> mentioned previously.
> - Fragment #expression-Entity introduces an "entity expression" which 
> is the ASN construct that describes an "identifiable characterized thing"
>
> These are all very helpful clarifications over what we had previously, 
> and I'm particularly pleased that there is clarity here about the 
> distinction between an ASN language construct and the thing it describes.
>
> My comment is this:  now that "entity expression" is used to refer to 
> the language construct, the term "entity" can unambiguously refer to 
> the thing described by that construct; i.e. the characterized thing.  
> Indeed, this is already suggested by the diagram at #prov-dm-overview.
>
> Then, I would say that in the entity expression:
>
>   entity(e0, [ type="File", location="/shared/crime.txt", 
> creator="Alice" ])
>
> the identifier e0 *denotes* the described *entity* (which we read is a 
> file at location "/shared/crime.txt" created by Alice).
>
> and from the expression and assertions from the surrounding story:
>
>   entity(e2, [ type="File", location="/shared/crime.txt", 
> creator="Alice",
>                content="There was a lot of crime in London last month."])
>
> we can say that identifier e2 denotes another entity that is a 
> particular view of the entity e0, which happens to contain the text 
> "There was a lot of crime in London last month."
>
> I've somewhat laboured this, but what I'm suggesting is that the 
> concept "entity" can be used to mean what has been introduced as a 
> "characterized thing".
>
> ...

-- 
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