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

Re: Models and their use

From: Graham Klyne <GK@ninebynine.org>
Date: Tue, 12 Jul 2011 17:02:23 +0100
Message-ID: <4E1C700F.9030602@ninebynine.org>
To: Simon Miles <simon.miles@kcl.ac.uk>
CC: Provenance Working Group WG <public-prov-wg@w3.org>
Simon Miles wrote:
 > To understand the consequences of the above points, I suggest
 > alternative definitions at the link below:
 >   http://www.w3.org/2011/prov/wiki/Talk:F2F1ConceptDefinitions#Entity_and_IVP_of

+1

I think this is a big improvement over what we have.

#g
--

Simon Miles wrote:
> Hello,
> 
> I raised a point with Luc and Jim (McC) at the F2F1, but did not have
> time to mention it in discussion. It primarily concerns the definition
> of Thing/Stuff/Entity/Entity State/BOB.
> 
> I think complexity and confusion arises from talking about "modelling"
> and "representing" in the model itself. The concepts comprising a
> model should be just whatever is modelled, e.g. "process execution",
> not how the model is used, e.g. "representation of a process
> execution".
> 
> It should already be clearly understood by users, but can be stated
> explicitly, that in using any model you are asserting something about
> whatever is modelled using some representation of it. We may also add
> that any assertion is by necessity from some perspective, of which
> there may be many, and not necessarily objectively true. These points
> are separate from any concept definition.
> 
> A connected point is that definitions in models will use colloquial
> synonyms to get across what a concept is, and these do not need to be
> defined, e.g. we do not define "activity" even though we say "a
> process execution is an activity..."
> 
> I think we got the above wrong for Thing, in saying:
>  "things represent real-world stuffs and have properties modeling
> aspects of stuff states"
> changed to:
>  "BOBs represent real-world entities and have properties modeling
> aspects of entity states"
> 
> First, this definition uses terms "represent" and "modeling", implying
> it is about the use of the model not what is modelled. Second, the F2F
> discussion ended up with "entity", the replacement of "stuff", being
> treated as a concept in the model itself rather than a colloquial
> synonym used for the purpose of definition, e.g. we discussed whether
> an agent is an entity or an entity state (or a BOB).
> 
> I argue we should be clear that there is only one concept being
> defined here not two, and it is something in the world not a
> representation of it. If we need to, we can say how users should apply
> the model in accompanying notes.
> 
> A similar problem may affect the IPV-of definition, where properties
> are referred to having "corresponding" values. I think they have the
> *same* values, which may be represented in different ways. The former
> is a constraint of the model, while the latter is a given truth about
> the use of any model.
> 
> To understand the consequences of the above points, I suggest
> alternative definitions at the link below:
>   http://www.w3.org/2011/prov/wiki/Talk:F2F1ConceptDefinitions#Entity_and_IVP_of
> 
> Thanks,
> Simon
> 
Received on Tuesday, 12 July 2011 16:03:09 GMT

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