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re: IVPof proposal (was Re: Models and their use)

From: Myers, Jim <MYERSJ4@rpi.edu>
Date: Thu, 14 Jul 2011 16:17:42 -0400
Message-ID: <B7376F3FB29F7E42A510EB5026D99EF2053FFED5@troy-be-ex2.win.rpi.edu>
To: <public-prov-wg@w3.org>

 Simon - comments within...

> > I'm asking about what is being asserted with IVP of - Halley's-near-the-sun
> is an IVP of "Halley's" and not "Kahoutek's" because... ? We know it's not
> because of the cosmetic similarity of the ID strings, and, as far as we know,
> there are no formal relationships between the 'comet' and comet-near-the-
> sun' classes/ontologies (I'm assuming this is the general case). In common
> sense terms, we have some notion that, at least at some times, there is
> 'stuff' - the rocks/dust/water/etc. in "Halley's" and "Halley's-near-the-sun"
> that  is common to both ("comet" could mean just the nucleus and "comet-
> near-the-sun" might include water in the tail, so there may still only be partial
> overall of the set of particles in both). Stuff was aimed at that level - there's
> something more fundamental than the notion of comet, such as a 'set of
> particles/molecules' (if you believe in those), and at that level of
> representation Halley's and Halley's-near-the-sun have some common set
> members in that representation, whereas Kahoutek and Halley's-near-the-
> sun do not. If you believe in wave functions, string theory, etc. you may
> disagree what the right level for assessing commonality is.
> 
> I understand and agree my definition of IVP does not explicitly convey that
> connection. But my definition does say "everything invariant about A is also
> invariant about B" and I can't see how Halley's-near-the-sun could be an
> invariant view of Kahoutek's comet under this definition. While there may be
> invariant properties of a thing which are not part of its identity, surely every
> aspect of its identity is itself invariant?

I have a couple of concerns:

I think we will have trouble making this hierarchical ("everything invariant about A is also invariant about B")- a comet has an elliptical orbit that is ~fixed (not really, but close) whereas a comet-near-the-sun goes in an open arc, a comet may have a fixed size/shape, a comet-near-the-sun changes its size/shape (tail and coma). (But we still have the comet having a no-tail/tailed stage property that is invariant (tailed) for comet-near-the-sun, so there's one property that works per your definition and it does make sense to think in IVPof terms).

I could go farther and talk about the comet(s)-closest-to-the-sun - it could be interesting to track the evolution of that to know whether there were periods in history where no one saw a bright comet, etc. If I do that (or some well-meaning user of the standard does), how can we define IVPof in a useful way? Without trying to get into an argument about the ultimate nature or reality, I think the notion of 'closest-comet-to-the-sun', while it is well defined and can have provenance etc., is theoretical/already assumes a perspective about reality. If I think in terms of molecules, I can see comets themselves in the same way - they are a perspective on reality - and I don't see a clear hierarchy in general, or a simple relationship of their properties. The best I've come up with is to think in terms of stuff - some third perspective where we'd agree that, at the point we assert the IVPof relationship, both of the theoretical entities we're talking about would overlap in that third ontology (i.e. set of molecules).  I don't think we can require in the general case that there's a sameAs of stateOf connection directly between the two ontologies.

Another direction might be to talk about the existence of some coordinate system in which IVPof implies the two things occupy the same 'space' - real outer space for comets and comets-near-the-sun. 

> 
> > If we don't like 'stuff' and don't want to talk about entities as
> representation of /conceptualization of stuff as a way to define what IVP of
> means, what's the alternative being proposed?
> 
> I don't mind 'stuff' as long as it is treated as an undefined, explanatory part of
> a concept definition and not a concept itself (not that I think you are
> suggesting this, but it is how the F2F ended). I have used 'anything' in a
> similar vein to 'stuff' in my definition. I am arguing against entities as
> representations.
> 
OK - I think I am trying to use stuff, and entities in the sense of instances of classes in other ontologies, as external to the model/part of the definition of concepts rather than as additional constructs in the model.

> > Not sure I can parse this. I would say the neither comets nor comets-near-
> the-sun are real or representations of each other - they are theoretical
> constructs that are a useful shorthand in talking about more fundamental
> stuff and the processes that affect it.
> 
> For our purposes, I do not see how it is helpful to say comets (or
> webpages) are not real :-)

This is what science is all about! Pretend the comet doesn't exist and focus on the set of molecules that are currently traveling together due to gravity and you'll learn something new (some molecules leave comets and become shooting stars!). Pretend the web page is not real and focus on the text itself and you can track the evolution of the meme... The only thing I want to challenge is the supremacy of one view over the others as to what is a real thing and what is a perceived/derived/theoretical conceptualization.

However, yes - this is not a provenance standard to describe the history of fictional stuff... 

> 
> The definition of dc:Agent, "A resource that acts or has the power to act.
> Examples of Agent include person, organization, and software agent.", does
> not obviously distinguish between reality and representation, because it is
> given that we are talking about the former so that we can create the latter
> using DC terms. I don't understand why this form of definition could not be
> created for pil:Thing.
> 
I think this is more about the 'nature of a bob', but... 

I agree, but I would say that the way dc represents people, orgs, etc. is as agents and that dc does not consider agents to have heights or employees and therefore there is still a distinction between agent and person. How does DC address people's interest in finding all books generated by agents who are people under 5 feet tall?

> > I would like to assert an IVP relationship between things/entities in these
> two constructs  when I believe those entities are different ways of talking
> about the same stuff and when the entity on the invariant end of the
> relationship is more appropriate for discussing the occurrence of certain
> types of processes (certain process executions) because that theoretical
> construct it is defined in terms of results in a new entity when the process
> execution occurs (versus merely changing property values in the other
> theoretical construct).
> 
> Agreed.
> 
> > OK - so no disagreement that IVP of is not hierarchical in the general case?
> 
> I'm not sure. I intuitively thought of it as hierarchical, but your arguments to
> Stephen may have persuaded me otherwise. But it seems a separate issue
> from this thread, unless I'm missing the connection?

The connect is just that I can't find a reasonable definition for a non-hierarchical  IVPof without invoking 'stuff' or a coordinate system as above. 
> 
> > The discussion of IVP of implying a connection between mutable and
> invariant properties was actually an attempt to avoid talking about 'relative to
> a process' and I think implicitly was a way to define the perspective just in
> terms of the "A IVPof B" statement. That attempt might be a cause of the
> complexity that is being discussed.
> 
> OK, I didn't get that connection. I agree that defining perspective using IPVof,
> rather than adding to the complexity of entity itself, is sensible.
> 
> > To answer "is this adequate?", I still have to understand what concrete
> change this makes to the model:
> >
> > You state "from some perspective" above, but I tend to think of IVP as
> involving a shift in perspective - is that still consistent with your proposal -
> that different assertions separated by IVP relationships could have different
> perspectives?
> >
> > And is the argument then basically that any attempt to formalize the
> 'perspective' leads to complexity/confusion that we should avoid? If so, it
> sounds tempting but I would be concerned if that ends up making it
> impossible to assess an IVPof assertion - e.g. if I did know the set of particles
> in "Halley's" and "Kahoutek's-near-the-sun", can I make any assessment of
> whether "Kahoutek-near-the-sun" is an IVPof "Halley's" is a valid assertion
> (or less stringently, that I should trust other statements of the asserter)? If
> the idea is to drop the constraints on properties, but to preserve this level of
> meaning of IVPof, then I think it's useful. If we completely lose the ability to
> make truth/trust assessments about IVPof assertions (using knowledge
> external to the model as would be the case with recipe links and assessing
> truth/trust in process execution assertions), then I think it goes too far.
> 
> I think this is discussion is now based on the equivalence between "relative
> to a process" and "invariant properties" mentioned above, which I am still
> trying to get my head around. What I can say is that I still refer to "everything
> invariant about [an entity]" in my definition of IVPof, so there may not be
> any fundamental disagreement.
> If the invariant properties conveyed a shift in perspective before, they still do
> in my revised version.
> 
OK -I think the challenge for sticking with a property-centric definition is that the perspective shift can change what properties make sense - that's what drove Luc and I to the 'corresponding'/related properties language from assuming that the properties had to be the same.

> > I fear we may still not be talking the same language, but let's see -
> hopefully we can converge.
> 
> I agree fully with that :-)

Makes me wonder how we all function daily...

 Jim


> 
> Thanks,
> Simon
> 
> >  Jim
> >
> >
> >
> >
> >>
> >> Thanks,
> >> Simon
> >>
> >>
> >> >  Thanks,
> >> >  Jim
> >> >
> >> >
> >> >
> >> >
> >> >> -----Original Message-----
> >> >> From: public-prov-wg-request@w3.org [mailto:public-prov-wg-
> >> >> request@w3.org] On Behalf Of Simon Miles
> >> >> Sent: Wednesday, July 13, 2011 8:36 AM
> >> >> To: Provenance Working Group WG
> >> >> Subject: Re: Models and their use
> >> >>
> >> >> Jim, Graham,
> >> >>
> >> >> Reading through your comments, I'm pretty much in agreement with
> >> them.
> >> >> The discrepancy between my view and Jim's is, I think, just a
> >> >> matter of what we assume is being defined at the moment (i.e. by
> entity/thing).
> >> >>
> >> >> As in Graham's last mail, I am assuming that we are first defining
> >> >> any
> >> >> (contextualised) entity ((1) in Graham's classification).
> >> >>
> >> >> I fully agree with you that assertion/observation/description (2)
> >> >> is also an important and distinct concept. However, I see it as
> >> >> secondary to the idea of entity in the model and, as Graham says,
> >> >> a description is itself a kind of entity. This may be comparable
> >> >> to agents or process executions, i.e. agents, executions and
> >> >> descriptions are all particularly important (for provenance)
> >> >> subclasses of
> >> entity.
> >> >>
> >> >> And I think this difference in our views about what was being
> >> >> defined by "thing" nicely illustrates the original point I was
> >> >> trying to make about the conflation in the definition :-)
> >> >>
> >> >> Thanks,
> >> >> Simon
> >> >>
> >> >> On 13 July 2011 11:01, Graham Klyne <GK@ninebynine.org> wrote:
> >> >> > Jim,
> >> >> >
> >> >> > I've been thinking about your comments, and have come to a view
> >> >> > that there are two things going on here, which are not being
> >> >> > clearly
> >> >> distinguished:
> >> >> >
> >> >> > 1. an entity constrained to some context
> >> >> >
> >> >> > 2. observations or descriptions of an entity
> >> >> >
> >> >> > which when combined can model observations/descriptions of an
> >> >> > entity constrained to some context.  I have been focusing on
> >> >> > (1), with the expectation that (2) would be dealt with
> >> >> > separately in the model, where provenance is a kind of
> >> >> > description.  If I understand correctly, you are particularly
> >> >> > concerned to distinguish between entity and description.  It
> >> >> > seems to me that "bob" has been adopted variously to fulfil
> >> >> both these distinctions.
> >> >> >
> >> >> > ...
> >> >> >
> >> >> > Example: suppose we're interested in Halley's comet, and in
> >> >> > particular in the periods when it is close to the sun or visible
> >> >> > from earth.  So we have two
> >> >> > concepts:  Halley's comet and Halleys comet when close to Earth.
> >> >> > To my mind, these are both *entities* (sensu F2F1).  Any
> >> >> > description that is true of Halley's comet generally should also
> >> >> > be true of it when close to Earth, but there are many other
> >> >> > assertions are true the constrained Halley's comet that are
> >> >> > probably not true at all times (e.g. the appearance of a tail
> >> >> > due to expulsion of gas and dust caused by
> >> >> solar heating).
> >> >> >
> >> >> > The page http://en.wikipedia.org/wiki/Halley's_Comet is a
> >> >> > *description* of Halley's comet.  Being a Wikipedia page, it
> >> >> > probably changes over time.  So we may wish to discuss it as it
> >> >> > exists in a particular period of time.  Today, for example, it
> >> >> > contains a list of
> >> >> > 95 references indicating sources of information used in the page.
> >> >> > Thus we may expect this page to be a description of Halley's
> >> >> > comet for its entire lifetime, but needs to be constrained to
> >> >> > make statements about the number of references it contains.  In
> >> >> > this respect, the page is
> >> >> both an "entity" and a "description" of an entity.
> >> >> >
> >> >> > The page at http://en.wikipedia.org/wiki/Halley's_Comet also has
> >> >> > a brief description of a Cuneiform-inscribed clay tablet which
> >> >> > is both an entity in its own right, with its own description and
> >> >> > provenance,
> >> >> > *and* a record of observation of Halley's comet.  I don't think
> >> >> > we can easily disjoin the class of descriptions from the class of
> entities.
> >> >> >
> >> >> > Thus, I perceive that the notion of constraint so that some
> >> >> > aspects of a constrained entity are invariant needs to be dealt
> >> >> > with separately from the notion of description, which often (but
> >> >> > not always, I think) applies to a constrained form of some entity.
> >> >> >
> >> >> > Does this make any sense?
> >> >> >
> >> >> > #g
> >> >> > --
> >> >> >
> >> >> >
> >> >> > Jim McCusker wrote:
> >> >> >> My issue is more with Simon's desire to conflate things with
> >> >> >> the descriptions of those things. We need to be able to say "x,
> >> >> >> as described by y", which is a separate issue from relating
> >> >> >> "x1" as an invariant view of "x2".
> >> >> >>
> >> >> >> "x as described by y" can be done in semweb using a URI for X
> >> >> >> and the URI for a named graph or graph literal for y, assuming
> >> >> >> that there are assertions in y about x. Another alternative is
> >> >> >> that y can be discussed as an information artifact, as in the
> >> >> >> Information Artifact Ontology
> >> >> >> (http://code.google.com/p/information-artifact-
> >> ontology).
> >> >> >> Since x changes over time, we need something that nails down
> >> >> >> what was actually "seen", or at least, claimed when the agent
> >> >> >> identified x in its context.
> >> >> >>
> >> >> >> A BOB is the y in the above paragraph, and I think that the
> >> >> >> fact that it's something that's describing an x, it must have
> >> >> >> the extra qualification in place in its name.
> >> >> >>
> >> >> >> Jim
> >> >> >>
> >> >> >> On Tue, Jul 12, 2011 at 3:27 PM, Graham Klyne
> >> >> >> <GK@ninebynine.org>
> >> >> wrote:
> >> >> >>> [Off-list]
> >> >> >>>
> >> >> >>> Jim,
> >> >> >>>
> >> >> >>> I had some small reservations about Simon's definition, but I
> >> >> >>> felt that it was such a big improvement over what we currently
> >> >> >>> have that I didn't want to muddy the waters just yet by adding
> >> >> >>> qualifications to my support :)
> >> >> >>>
> >> >> >>> (Specifically, I would remove "and something more is invariant
> >> >> >>> about B" from the efinition of invariant view, so that
> >> >> >>> anything can be an invariant view of itself (or not excluded
> >> >> >>> from so
> >> >> >>> being) - which I think is one of the concerns you raised.)
> >> >> >>>
> >> >> >>> Apart from that, I think there is an aspect of an invariant
> >> >> >>> view that is in some sense fundamentally subsumptive -- there
> >> >> >>> is a distinct sense that A and B are generally the same,
> >> >> >>> except that one may
> >> >> be more constrained.
> >> >> >>>
> >> >> >>> But, more importantly, I think we need to be looking to say
> >> >> >>> less, not
> >> >> more.
> >> >> >>> I feel that Simon's definition captures close to what we need
> >> >> >>> to say without adding too much more.
> >> >> >>>
> >> >> >>> In this, I'm arguing for the minimum useful semantics - it's
> >> >> >>> easier to add (or layer) constraints later than to remove them
> >> >> >>> from an established defintion.  By providing a little as we
> >> >> >>> can for people to disagree with, I think we maximize the
> >> >> >>> potential for take-up of the
> >> >> WG outputs.
> >> >> >>>
> >> >> >>> #g
> >> >> >>> --
> >> >> >>>
> >> >> >>>
> >> >> >>> Jim McCusker wrote:
> >> >> >>>> On Tue, Jul 12, 2011 at 12:02 PM, Graham Klyne
> >> >> >>>> <GK@ninebynine.org>
> >> >> wrote:
> >> >> >>>>> Simon Miles wrote:
> >> >> >>>>>> To understand the consequences of the above points, I
> >> >> >>>>>> suggest alternative definitions at the link below:
> >> >> >>>>>>
> >> >> >>>>>>
> >> >> >>>>>>
> >> >> http://www.w3.org/2011/prov/wiki/Talk:F2F1ConceptDefinitions#Enti
> >> >> >>>>>> ty_and_IVP_of
> >> >> >>>>> +1
> >> >> >>>>>
> >> >> >>>>> I think this is a big improvement over what we have.
> >> >> >>>> I like the Entity definition, but I'm not sure how we then go
> >> >> >>>> about qualifying assertions about Entities. We need a way of
> >> >> >>>> making those assertions (which is what BOBs were for) and a
> >> >> >>>> way of relating Entities that are the same, even if they
> >> >> >>>> aren't mathematically the same (different state, different
> >> >> >>>> aspect, etc.). IVP of as it's defined there is not quite
> >> >> >>>> enough, since it only allows for relations between entities
> >> >> >>>> that have subsumptive (a is IVP of b, therefore a has all the
> >> >> >>>> states of b plus
> >> some).
> >> >> >>>>
> >> >> >>>> Jim
> >> >> >>>> --
> >> >> >>>> Jim McCusker
> >> >> >>>> Programmer Analyst
> >> >> >>>> Krauthammer Lab, Pathology Informatics Yale School of
> >> >> >>>> Medicine james.mccusker@yale.edu | (203) 785-6330
> >> >> >>>> http://krauthammerlab.med.yale.edu
> >> >> >>>>
> >> >> >>>> PhD Student
> >> >> >>>> Tetherless World Constellation Rensselaer Polytechnic
> >> >> >>>> Institute mccusj@cs.rpi.edu http://tw.rpi.edu
> >> >> >>>>
> >> >> >>>
> >> >> >>>
> >> >> >>
> >> >> >>
> >> >> >>
> >> >> >
> >> >> >
> >> >> >
> >> >>
> >>
> __________________________________________________________
> >> >> ____________
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> >> >> >
> >> >>
> >>
> __________________________________________________________
> >> >> ____________
> >> >> >
> >> >>
> >> >>
> >> >>
> >> >> --
> >> >> Dr Simon Miles
> >> >> Lecturer, Department of Informatics
> >> >> Kings College London, WC2R 2LS, UK
> >> >> +44 (0)20 7848 1166
> >> >
> >> >
> >> >
> >>
> __________________________________________________________
> >> ____________
> >> > This email has been scanned by the MessageLabs Email Security System.
> >> > For more information please visit http://www.messagelabs.com/email
> >> >
> >>
> __________________________________________________________
> >> ____________
> >> >
> >>
> >>
> >>
> >> --
> >> Dr Simon Miles
> >> Lecturer, Department of Informatics
> >> Kings College London, WC2R 2LS, UK
> >> +44 (0)20 7848 1166
> >
> >
> >
> >
> __________________________________________________________
> ____________
> > This email has been scanned by the MessageLabs Email Security System.
> > For more information please visit http://www.messagelabs.com/email
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> __________________________________________________________
> ____________
> >
> 
> 
> 
> --
> Dr Simon Miles
> Lecturer, Department of Informatics
> Kings College London, WC2R 2LS, UK
> +44 (0)20 7848 1166
Received on Thursday, 14 July 2011 20:19:02 GMT

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