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Re: Definitions and provenance and invariance

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Thu, 16 Jun 2011 15:48:37 +0100
Message-ID: <EMEW3|ce3801c5b0b13d9537fe13a4d4833517n5FFmi08L.Moreau|ecs.soton.ac.uk|4DFA17C5.4080407@ecs.soton.ac.uk>
To: public-prov-wg@w3.org
Hi Stian
Can you show in this encoding how the editing process by David extends 
the previous
version of the file with two more lines?
Thanks,
Luc

On 06/16/2011 03:37 PM, Stian Soiland-Reyes 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.
>
>    

-- 
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 Thursday, 16 June 2011 14:49:23 GMT

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