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Re: complementOf -> viewOf: proposed text

From: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
Date: Thu, 19 Jan 2012 14:08:16 +0000
Message-ID: <CAPRnXtk9z67Ztk8w=W-Nm3gjSmz9HA5xY4qWy_HZwoeVy9P-8g@mail.gmail.com>
To: "Myers, Jim" <MYERSJ4@rpi.edu>
Cc: Luc Moreau <L.Moreau@ecs.soton.ac.uk>, Paolo Missier <Paolo.Missier@ncl.ac.uk>, Paolo Missier <paolo.missier@newcastle.ac.uk>, "public-prov-wg@w3.org" <public-prov-wg@w3.org>
Thanks for a great summary!

On Thu, Jan 19, 2012 at 13:29, Myers, Jim <MYERSJ4@rpi.edu> wrote:


> Alternate is so hard to define because we're are having to define entities in terms of the things that people have named, which are not prov:things - they are prov:things that have some characterization in terms of some theory of the world.  (When fully characterized with respect to what the asserter wants to report, we have entities.)

Agree - although I would argue that they are entities no matter how
'fully' they are characterised. As long as the asserter has some kind
of implicit or explicit idea about what the entity is and is willing
to use them in the provenance account, then they are characterised. It
could be as little implicit as simply entity(paolo).


> So two choices (could we vote?):

At least informally..?


> Alternative applies only between two entities that characterize the same prov:thing over the same interval and is transitive: to use it in the customer-in-chair case you have to create specializations of both poalo and customer in chair.

So in my silly usecase, there would be a paoloInChair (specialization
of paolo) and customerInChairFrom5pmTo6pm (specialisation of
customerInChair), and these are alternateOf each other (but don't have
a common specialisation).

Does it mean their generation and destruction time have to be the same
for alternates?

If not, then what does 'same interval' mean in alternativeOf(A,B)?
Lifetime of A is fully contained by lifetime of B? Or just that they
characterized the same thing during the complete time they overlapped?


> Alternative applies between entities that at some point in their lifecycles describe the same prov:thing. Transitivity cannot be applied. Having a time/event interval specified on the relationship would allow inference that there are specializations of both entities that are aliases (symmetric specializations of each other?) Pseudotransitivity in this way could be a separate vote...

-1 - this is the old ivpOf with its confusing interval overlap. This
easily covers the customerInRedChair example, but as the overlap
(where the characterisation is true) can be anything from tiny to
fully contained it is not that useful concept.


-- 
Stian Soiland-Reyes, myGrid team
School of Computer Science
The University of Manchester
Received on Thursday, 19 January 2012 14:09:06 UTC

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