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Re: Definitions and provenance and invariance

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Mon, 20 Jun 2011 16:08:21 +0100
Message-ID: <EMEW3|8b346a5dd6116e049e33e7f620506750n5JG8Q08L.Moreau|ecs.soton.ac.uk|4DFF6265.4060202@ecs.soton.ac.uk>
To: Graham Klyne <GK@ninebynine.org>
CC: public-prov-wg@w3.org
Thanks Graham.  As just said to Simon, I will draft a new version of the 
definition.
Luc

On 06/20/2011 02:31 PM, Graham Klyne wrote:
> I can (*), but I'm not sure it helps our main goals.
>
> #g
> -- 
>
> (*) to me, it implies some feature that is fundamental to 
> "identifying" (**): defining what makes en entity what it is, and what 
> distinguishes it from other entities.  The colour of my eyes is not, 
> in my view, such a feature.
>
>
> (**)
>
> (a) "to recognize or establish as being a particular person or thing"
> -- http://dictionary.reference.com/browse/identify
>
> (b) "establish or indicate who or what (someone or something) is"
> -- http://oxforddictionaries.com/definition/identify
>
>
> Luc Moreau wrote:
>> You may be right,  can you explain how you understand it?
>> Luc
>>
>> On 06/20/2011 11:22 AM, Graham Klyne wrote:
>>> It seems we understand the phrase "integral to identity" somewhat 
>>> differently, so that's a different reason not use it as part of the 
>>> definitions of "things" and "invariant views".  The more you say, 
>>> the more room there is for disagreement ...
>>>
>>> #g
>>> -- 
>>>
>>> Luc Moreau wrote:
>>>> Hi Simon and Graham,
>>>>
>>>> I added a response to Graham's comment on invariant property and 
>>>> identity.
>>>> See 
>>>> http://www.w3.org/2011/prov/wiki/ConceptInvariantViewOnThing#Comments
>>>>
>>>> Cheers,
>>>> Luc
>>>>
>>>> On 06/19/2011 12:18 PM, Simon Miles wrote:
>>>>> Graham,
>>>>>
>>>>> OK, thanks for the clarification. I agree with your point, and am 
>>>>> also
>>>>> sympathetic to your discomfort with everything invariant being
>>>>> "integral to identity".
>>>>>
>>>>> Thanks,
>>>>> Simon
>>>>>
>>>>>
>>>>> On 17 June 2011 23:00, Graham Klyne<GK@ninebynine.org>  wrote:
>>>>>> Simon Miles wrote:
>>>>>>> Graham, Stian, all,
>>>>>>>
>>>>>>> I might be confused, but this seems a more complex model than 
>>>>>>> the one
>>>>>>> proposed by Jim and Luc.  Why do we need to both a Dynamic Resource
>>>>>>> and a View Resource?  I can't see any meaningful difference between
>>>>>>> them either in Graham's definition or Stian's (helpful) concrete
>>>>>>> example.  What is the point of saying anything about a mutable
>>>>>>> property, e.g. "content of DynamicResource i0", when any 
>>>>>>> assertion of
>>>>>>> a mutable property's value will not always hold anyway?
>>>>>> Speaking for myself... I used the terms "Dynamic" and "View" as 
>>>>>> labels to
>>>>>> distinguish their roles in the structure given.  I would not 
>>>>>> choose to model
>>>>>> them as different types.
>>>>>>
>>>>>> My point, expressed in terms of Stian's example, is that the 
>>>>>> notion we have been
>>>>>> calling IVP is present in the viewOf relation rather than 
>>>>>> inherent in the
>>>>>> resources themselves.  This was my point, which I think is also 
>>>>>> at the heart of
>>>>>> the proposal by Jim and Luc.
>>>>>>
>>>>>> I happen to think that the definition as proposed in the wiki at
>>>>>> http://www.w3.org/2011/prov/wiki/ConceptInvariantViewOnThing#ACCEPTED_at_teleconference_2011-06-16 
>>>>>>
>>>>>> is over-specified (I've added some comments there).  But having 
>>>>>> expressed that
>>>>>> reservation, I'm content to let them stand pro tem for the 
>>>>>> purposes of discussion.
>>>>>>
>>>>>> #g
>>>>>> -- 
>>>>>>
>>>>>>
>>>>>>> On 16 June 2011 15:39, Stian Soiland-Reyes
>>>>>>> <soiland-reyes@cs.manchester.ac.uk>  wrote:
>>>>>>>> On Tue, Jun 14, 2011 at 12:09, Graham Klyne<GK@ninebynine.org>  
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>> Suppose that the "Dynamic resource has a number of different 
>>>>>>>>> observable
>>>>>>>>> properties, some of which do not change over time, and others 
>>>>>>>>> which do.
>>>>>>>>>   Then the View resource would be a resource for with a 
>>>>>>>>> similar set of
>>>>>>>>> properties such that do not change over time, but correspond 
>>>>>>>>> to the dynamic
>>>>>>>>> resource properties at a given time (including properties that 
>>>>>>>>> do not change
>>>>>>>>> over time).  If the Dynamic resource does not change over 
>>>>>>>>> time, then it may
>>>>>>>>> also serve as its own view resource:  the has view property 
>>>>>>>>> can be
>>>>>>>>> reflexive.
>>>>>>>>>
>>>>>>>>> The provenance resource is an assertion about the properties 
>>>>>>>>> of the view
>>>>>>>>> resource.  I believe the key requirement that we try to 
>>>>>>>>> capture is that the
>>>>>>>>> properties about which the provenance resource makes 
>>>>>>>>> assertions are
>>>>>>>>> invariant - there is no assertion in the provenance resource 
>>>>>>>>> which is not
>>>>>>>>> always true of the view resource.
>>>>>>>> This is a very beautifully simple model which I think we should 
>>>>>>>> keep
>>>>>>>> in mind before digging too much into the exciting discussions.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> "simplified" for the File example:
>>>>>>>>
>>>>>>>>
>>>>>>>> :i0 a :DynamicResource ;
>>>>>>>>   :name "/home/towns.txt" ;
>>>>>>>>   :content [ :bytes "" ] ;
>>>>>>>>   :creator :Alice .
>>>>>>>>
>>>>>>>>
>>>>>>>> :i0View a :ViewResource ;
>>>>>>>>    :viewOf :i0 ;
>>>>>>>>    :name "/home/towns.txt" ;
>>>>>>>>    :creator :Alice .
>>>>>>>>
>>>>>>>>
>>>>>>>> # Metadata stored in filesystem
>>>>>>>> :i0Provenance a :ProvenanceResource ;
>>>>>>>>    :provenanceOf :i0View ;
>>>>>>>>    :account :FileSystem ;
>>>>>>>>    :processes (
>>>>>>>>       [  :agent :Alice ;
>>>>>>>>          :location :server1 ;
>>>>>>>>          :process :fileCreation ;
>>>>>>>>          :time "2011-06-15 18:00:01 UTC"  ]
>>>>>>>>     ) .
>>>>>>>>
>>>>>>>> # however the log file claims the file was created on her 
>>>>>>>> workstation
>>>>>>>> (not server), and 1 second later (clocks out of sync?)
>>>>>>>>
>>>>>>>> :i0Provenance2 a :ProvenanceResource ;
>>>>>>>>    :provenanceOf :i0View ;
>>>>>>>>    :account :ServerLogFile ;
>>>>>>>>    :processes (
>>>>>>>>       [  :agent :Alice ;
>>>>>>>>          :location :AliceWorkstation;
>>>>>>>>          :process :fileCreation ;
>>>>>>>>          :time "2011-06-15 18:00:02 UTC"  ]
>>>>>>>>     ) .
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> ### New graph - Content changed
>>>>>>>>
>>>>>>>> :i0 a :DynamicResource ;
>>>>>>>>   :content [ :bytes "New York\nLos Angeles\n"  ] ;
>>>>>>>>   :name "/home/towns.txt" ;
>>>>>>>>   :creator :Alice ;
>>>>>>>>   :readBy (:Alice :Bob :Charles :David)
>>>>>>>>
>>>>>>>>
>>>>>>>> :i2 a :ViewResource ;
>>>>>>>>   :viewOf :i0 ;
>>>>>>>>   :name "/home/towns.txt" ;
>>>>>>>>   :creator :Alice ;
>>>>>>>>   :content [ :bytes "New York\nLos Angeles\n"  ] .
>>>>>>>>
>>>>>>>> :i2Provenance a :ProvenanceResource ;
>>>>>>>>   :provenanceOf :i2 ;
>>>>>>>>    :account :FileSystem ;
>>>>>>>>    :processes (
>>>>>>>>       [  :agent :Alice ;
>>>>>>>>          :location :server1 ;
>>>>>>>>          :process :fileCreation ;
>>>>>>>>          :time "2011-06-15 18:00:03 UTC"  ]
>>>>>>>> # Lost as :FileSystem metadata only keeps last-modified
>>>>>>>> #     [   :agent :Alice ;
>>>>>>>> #         :location :server1 ;
>>>>>>>> #         :process :fileWrite ;
>>>>>>>> #         :time "2011-06-15 18:00:03 UTC"  ]
>>>>>>>>      [
>>>>>>>>          #  :agent :Bob;  - not recorded as only owner/creator 
>>>>>>>> is kept
>>>>>>>>          :location :server1 ;
>>>>>>>>          :process :fileWrite ;
>>>>>>>>          :time "2011-06-15 18:14:12 UTC"  ]
>>>>>>>>     ) .
>>>>>>>>
>>>>>>>>
>>>>>>>> So say there are additional mutable properties such as :readBy 
>>>>>>>> above -
>>>>>>>> would you consider those propagating into the view as mutable
>>>>>>>> properties? There could be another view over :i2 for the file 
>>>>>>>> before
>>>>>>>> it was read by Charles, where :readBy is an immutable property.
>>>>>>>>
>>>>>>>> The example graph above does not distinguish between mutable and
>>>>>>>> immutable properties - perhaps we shouldn't as they could be 
>>>>>>>> difficult
>>>>>>>> to find, identify and measure.
>>>>>>>>
>>>>>>>> Here :readBy is not kept by neither the log file or file system 
>>>>>>>> and is
>>>>>>>> a kind of conceptual property - it could be discovered by simply
>>>>>>>> asking everyone who could have read it, or inferred from traced 
>>>>>>>> file
>>>>>>>> usage, like if its sent in an email.
>>>>>>>>
>>>>>>>> -- 
>>>>>>>> Stian Soiland-Reyes, myGrid team
>>>>>>>> School of Computer Science
>>>>>>>> The University of Manchester
>>>>>>>>
>>>>>>>>
>>>>>>>> ______________________________________________________________________ 
>>>>>>>>
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>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> ______________________________________________________________________ 
>>>>>>
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>>>>>> ______________________________________________________________________ 
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>
>

-- 
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, 20 June 2011 15:08:56 GMT

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