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Re: [provo] Difference between wasInformedBy and wasStartedByActivity (ttl examples)

From: Timothy Lebo <lebot@rpi.edu>
Date: Mon, 7 May 2012 10:48:26 -0400
Cc: Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>, Jun Zhao <jun.zhao@zoo.ox.ac.uk>, W3C provenance WG <public-prov-wg@w3.org>
Message-Id: <A061D642-1C8B-4935-AC38-41F6258C6AC9@rpi.edu>
To: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
Stian,


On May 3, 2012, at 7:18 AM, Stian Soiland-Reyes wrote:

> I think in general your considerations are right.
> 
> 
> On Thu, May 3, 2012 at 11:23 AM, Khalid Belhajjame
> <Khalid.Belhajjame@cs.man.ac.uk> wrote:
> 
>> 
> 
> In http://dvcs.w3.org/hg/prov/raw-file/default/examples/eg-24-prov-o-html-examples/rdf/create/rdf/property_wasStartedByActivity.ttl
> I have changed the fuel-filling example:
> 
> :filling-fuel
>    a prov:Activity;
>    prov:startedAtTime        "2012-04-24T18:21:00Z"^^xsd:dateTime ;
>    prov:endedAtTime          "2012-04-24T18:23:10Z"^^xsd:dateTime ;
>    prov:wasAttributedTo      :driver ;
>    prov:wasStartedByActivity :observing-low-fuel .
> 
> :observing-low-fuel
>    a prov:Activity;
>    prov:wasAttributedTo      :driver ;
>    prov:startedAtTime        "2012-04-24T17:45:00Z"^^xsd:dateTime .
> 
> :driver a prov:Person, prov:Agent .
> 
> 
> So here, the entity is some kind of warning light, or it could be
> looking at the fuel meter, or perhaps it was a very old car that
> starts making 'coughing' sounds when there's low fuel. We don't know,
> and so we have not asserted that messaging entity, and we did not use
> prov:wasStartedBy. If you later see prov:wasStartedBy, you can say
> "Ah, that's the one".

Removing the "blinking light" from the fuel filling example motivates prov:wasStartedByActivity in a way that I haven't seen before.
Thanks!

> 
> 
> 
> I believe that if you use prov:wasStartedBy, then also saying
> prov:wasStartedByActivity is just restating the same in a blurrier
> manner according to the inference rules of PROV-constraints - like
> stating prov:tracedTo after stating a prov:wasDerivedFrom.

+1, repositioning wasStartedByActivity as a "blurrier" form of wasStartedBy seems to finally find a place for it in the model.
Though, like Khalid, I'm not sure it will be used much, or correctly.

> 
> This could still be appropriate for cases where you want to attach
> some properties to the wasStartedbyActivity relation, or where the
> activity-to-activity relation is much more important than the entity
> (I started investigating the accident, but it does not matter if I was
> told about the case by telephone or email), and so I agree on your
> proposed change to DM - the entity does not *need* to be unspecified.

How can it be reframed so that wasStartedByActivity can "grow" in details like Derivation does with hadActivity, hadUsage, and hadGeneration?

-Tim


> 
> 
> 
> -- 
> Stian Soiland-Reyes, myGrid team
> School of Computer Science
> The University of Manchester
> 
> 
Received on Monday, 7 May 2012 14:49:17 GMT

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