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Re: PROV-ISSUE-43 (derivation-time): Deriviation should have associated time [Conceptual Model]

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Fri, 11 Nov 2011 08:27:23 +0000
Message-ID: <EMEW3|8fa167c16d95448937721c44e16f5621nAA8RS08L.Moreau|ecs.soton.ac.uk|4EBCDC6B.6060405@ecs.soton.ac.uk>
To: Paul Groth <p.t.groth@vu.nl>
CC: "public-prov-wg@w3.org" <public-prov-wg@w3.org>
Hi Paul,

Comments interleaved.

On 11/09/2011 08:53 AM, Paul Groth wrote:
> Hi Luc,
>
> For me this is about, saying the following:
>
> blogpost wasDerivedFrom Report at 10am Thursday

What do you mean by this: blogpost was generated at 10am?

>
> Sure there is some process there, there may be an interval. But I just 
> don't want to assert all that information.

I understand, but ultimately, I am trying to determine whether there is 
a new special event 'derivation' to which
time is associated with, or whether we can reuse generation/use events 
or start/end events.

>
> Again, my fundamental thing is that I want to assert derivation chains 
> without (knowingly) asserting anything about process.
>
> Maybe the point is I'm looking for a shortcut such that if I assert a 
> time it automagically infers that the e2, and e1 are on the same time 
> line using the same clock and are the same time?

Inferring time line and same clock would be no good.

>
> Does that make sense?
>

I still need you to clarify the intended semantics, specifically, what 
notion of time you refer to.
Then, when it's decided, we can express the short cut.

My take on it, in the above example, you refer to the blogpost 
generation time.

> Paul

Luc
>
> Luc Moreau wrote:
>> Hi Paul,
>>
>> I'd like to come back to this issue, and see how we can solve it.
>>
>> The fully expanded notion of derivation, written
>> wasDerivedFrom(e2,e1,pe,q2,q1),
>> refers to the generation event for e2, and the use event for e1.
>> So, they form an "interval".  If we have time information for
>> each of these events (and assuming a same clock), we can compute the
>> duration
>> of this interval.
>>
>> So, the question is, do you really have a use case, where you don't want
>> to assert the use/generation events (qualified usage/generation) but 
>> want
>> to express time?  Can you explain it?
>>
>> My concern is that we are at risk of introducing two placeholders for
>> the same time information
>> (in derivation or use/generation events). Two placeholders for time may
>> result in inconsistent
>> information.
>>
>> Luc
>>
>>
>> On 07/23/2011 04:46 PM, Provenance Working Group Issue Tracker wrote:
>>> PROV-ISSUE-43 (derivation-time): Deriviation should have  associated 
>>> time [Conceptual Model]
>>>
>>> http://www.w3.org/2011/prov/track/issues/43
>>>
>>> Raised by: Paul Groth
>>> On product: Conceptual Model
>>>
>>> Other relationships have time associated with them (e.g. use, 
>>> generation, control)
>>>
>>> There is no optional time associated with derivation.
>>>
>>> Suggested resolution is to add the following to the definition of 
>>> isDerivedFrom:
>>>
>>> -  May contain a "derived from time" t, the time or time intervals 
>>> when b1 was derived from b2
>>>
>>> Example:
>>> isDerivedFrom(b1,b2, t)
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>

-- 
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 Friday, 11 November 2011 08:28:04 UTC

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