- From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- Date: Mon, 20 Jun 2011 16:06:20 +0100
- To: public-prov-wg@w3.org
Simon, OK with this. I was going to draft a further simplified definition taking this into account. Luc On 06/20/2011 01:45 PM, Simon Miles wrote: > Luc, > > I agree with Graham here. I think it's just a matter of wording, > nothing fundamental, but could lead to people misunderstanding the > model. > > I think the example you give of "identity" is what most people (or at > least I) would call a "distinguishing feature". Being integral to > identity is, colloquially, a stronger requirement: it suggests that > the property is important to understanding what that thing is, not > merely one that distinguishes the thing from other things. You could > argue that all distinguishing features are important from some > perspective, but I suggest that is not how "identity" is commonly > understood. > > As with Graham, I think we're more likely to get correct usage of the > model if we say nothing at all. I don't see a case for separating > distinguishing features from invariant properties in general. > > Thanks, > Simon > > On 20 June 2011 12:52, Luc Moreau<L.Moreau@ecs.soton.ac.uk> 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 >>>>>>>> >>>>>>>> >>>>>>>> ______________________________________________________________________ >>>>>>>> >>>>>>>> This email has been scanned by the MessageLabs Email Security >>>>>>>> System. >>>>>>>> For more information please visit http://www.messagelabs.com/email >>>>>>>> ______________________________________________________________________ >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> >>>>>> ______________________________________________________________________ >>>>>> This email has been scanned by the MessageLabs Email Security System. >>>>>> For more information please visit http://www.messagelabs.com/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 >> >> >> >> ______________________________________________________________________ >> This email has been scanned by the MessageLabs Email Security System. >> For more information please visit http://www.messagelabs.com/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 Monday, 20 June 2011 15:07:08 UTC