- From: Myers, Jim <MYERSJ4@rpi.edu>
- Date: Sat, 11 Jun 2011 12:17:54 -0400
- To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- CC: <public-prov-wg@w3c.org>
Sorry - I'm still having trouble understanding your issue - is 'relationship' the IVP of T relationship? (Should we try to arrange a call rather than exchange emails to make progress?) Jim -----Original Message----- From: Luc Moreau [mailto:L.Moreau@ecs.soton.ac.uk] Sent: Sat 6/11/2011 2:00 AM To: Myers, Jim Cc: public-prov-wg@w3c.org Subject: Re: PROV-ISSUE-8: defining generation in terms of `IVPT of' Jim, I had no concern. I wanted a clarification. - a point in time before which X does not exist, and after which it exists - a point in time within the duration of a process execution That's clear. I don't think the word relationship conveys this meaning of a transition/event/action though. Professor Luc Moreau Electronics and Computer Science University of Southampton Southampton SO17 1BJ United Kingdom On 11 Jun 2011, at 03:56, "Myers, Jim" <MYERSJ4@rpi.edu> wrote: > Luc, > I must be missing something = something is being generated/created by a process and you don't think that the sequence > Process start before X creation date before process ends is correct? If I'm phrasing it right, I think this is just the same set of constraints as in OPM for artifacts generated by a process. > > Would your concern be different if I said X is an IVPT as you are defining them? (I'd say X has an IVPT relation to Y but X would still be something like a cake that appears to derive from things that are clearly not cake-like/other states of cake). > > -- Jim > > On 10 Jun 2011, at 21:02, "Myers, Jim" <MYERSJ4@rpi.edu> wrote: > >>> >>> In this definition, you say when X didn't exist(before P) but you >> don't say >>> when it starts to exist. Is it intended? >> >> I updated the wiki as follows: >> * X did not exist before P began, >> * X began to exist sometime before P ended, and >> * X would not have begun existing if P had not occurred/P was necessary >> for X's existence to happen. > > Doesn't this say X began to exist between the start and end of P? > > Luc > > >> >>> >>> Also, did you really mean before P began? Can you explain why ? >> >> If X is generated by P, it can't have existed before P did. I think this >> is just saying P must start before the creation of X if X is generated >> by P. >> >> Is it a matter of wording or is something mixed up logically? >>> >>> Can X change, i don't understand what happens then? Does the last >> condition >>> necessarily apply? >> >> The generated thing/resource X can change after being generated, but >> only in ways consistent with its definition/type. An egg (defined as an >> ovoid object produced by a chicken) generated by a chicken can >> participate in boiling and painting (but I can't say what color such an >> egg is since color is not part of the definition of what makes one >> instance of the egg class unique/identifiable.) Other definitions of egg >> (IVPTs of each other) differ in how mutable they are. If you want a >> fairly immutable concept of egg, define it as a ovoid product of a >> chicken that has a particular color, is cooked/uncooked, >> cracked/uncracked, etc. Then we can talk about the Easter Egg that was >> derived from the uncooked/uncolored egg from a particular chicken >> through a series of processes. (Or, we could just say that after being >> generated, the egg sat and at some point we recognized that it existed >> in a state that corresponds to our notion of Easter egg and we assert >> that EasterEgg Y is an IVPT of egg X.) >> >> Does the last condition apply? - Is that "must there always be a Y that >> X is an IVPT of"? I don't know, but I suspect the answer is yes in any >> practical sense. By the IVPT definition I posted, all I need is some >> process P that would destroy/consume X and define Y as "X considered >> mutable with respect to P" - "the idea of this egg that would be >> unaffected even by the end of the universe" or some such might be the >> end of the line though. >>> >>> Are you also saying there needs to be another notion? Modification? >> >> I think the other notion is some form of participation (also uploaded >> definitions there). I was saying participates in/is modified by for the >> thing/process relationship. (Agency/control would be one form of >> participation). The egg layed by the chicken participates in boiling and >> coloring during its lifetime. It is not modified in the sense that any >> part of what identifies it changes, but attributes of it we consider >> transient (can't be used to discover this egg reliably because they >> change) do change. >> >> -- Jim >> >> >>> >>> Professor Luc Moreau >>> Electronics and Computer Science >>> University of Southampton >>> Southampton SO17 1BJ >>> United Kingdom >>> >>> On 10 Jun 2011, at 18:14, "Myers, Jim" <MYERSJ4@rpi.edu> wrote: >>> >>>> Posted on the wiki - basically the same definition as from Jun and >>>> Daniel with more discussion of how the IVPT concept and the idea of >>>> modifiable objects relate. >>>> -- Jim >>>> >>>>> -----Original Message----- >>>>> From: Luc Moreau [mailto:L.Moreau@ecs.soton.ac.uk] >>>>> Sent: Friday, June 10, 2011 12:57 PM >>>>> To: Myers, Jim >>>>> Cc: public-prov-wg@w3c.org >>>>> Subject: Re: PROV-ISSUE-8: defining generation in terms of `IVPT >> of' >>>>> >>>>> Jim and all, >>>>> >>>>> Could you put forward a revised definition that addresses better >> your >>>>> concerns? >>>>> >>>>> Professor Luc Moreau >>>>> Electronics and Computer Science >>>>> University of Southampton >>>>> Southampton SO17 1BJ >>>>> United Kingdom >>>>> >>>>> >>>>> On 10 Jun 2011, at 17:51, "Myers, Jim" <MYERSJ4@rpi.edu> wrote: >>>>> >>>>>> >>>>>>> >>>>>>> Hi Jim >>>>>>> I think we are discussing two issues here. >>>>>>> >>>>>>> 1. You suggest that the egg is itself an IVPT. >>>>>>> >>>>>>> There are different ways of looking at this: >>>>>>> a. I was saying that an egg was a thing (identified, and typed >>>>>> according to >>>>>>> an ontology) >>>>>>> Then, it's a question of choice of a same ontology, or >>>>>> ontology >>>>>>> refinement, a classical problem, >>>>>>> which we will not solve here. >>>>>> >>>>>> I would claim the things in IVPT relationships with egg are also >>>>>> things that can be identified, typed, etc., not necessarily in the >>>>>> same class or ontology as 'egg'. (A logical picture is not the >> same >>>>>> class of thing as a jpg file corresponding to a particular >>>>>> manifestation of that image). >>>>>> >>>>>>> >>>>>>> b. We could say that there is in an alternate account, which >>>>>> describes the >>>>>>> egg in terms of molecules. >>>>>> >>>>>> Yes - my object in that account is 'set of molecules' and 'egg' is >> a >>>>>> convenient label for when those molecules are in a particular >> subset >>>>>> of all the configurations they can be in. If you say egg is an >>>> object >>>>>> and require a different type of thing to be used to describe >> things >>>>>> that invariant views of my set of molecules, I can't use it in my >>>>>> account, and we don't yet have any mechanism to make it clear that >>>>>> somehow my 'state of set of molecules' corresponds to your notion >> of >>>> 'egg'. >>>>>> >>>>>>> >>>>>>> c. Alternatively, we have IVPTs of IVPTs of IVPTs ... >>>>>>> is there a base case? I fear we are going to reach quantum >>>>>> mechanics ... >>>>>> >>>>>> I don't think we have to be afraid of this - and I would rephrase >>>> and >>>>>> say we have things of different types that can be in IVPT >>>>>> relationships with each other and your concern is then whether the >>>>>> fact that we can make deep hierarchies is an issue. I'd answer >> that >>>> by >>>>>> saying that the base case is in the middle - things like eggs are >>>>>> useful not because they are somehow true objects where other >> things >>>>>> are just views, they are useful views because of the >> natural/common >>>>>> processes they participate in. The fact that the model allows one >> to >>>>>> describe a set of quantum wave functions and claim one view of >> them >>>> is >>>>>> an egg doesn't mean that this will happen in practice (though >> there >>>>>> are scientists who do essentially this on a daily basis at the >>>> nano-scale). >>>>>> >>>>>> Whether it is truly 'turtles all the way down' is a philosophical >>>>>> question I'm not sure we have to answer - modeling it that way >>>> covers >>>>>> the middle ground without requiring any connection to real base >>>>>> objects (or more neutrally, without identifying a particular set >> of >>>>>> objects as real with all others some form of constructed view) - >> in >>>>>> this sense, I would ask you a) whether you see a >>>>>> consequence/limitation of a model that does not define which >> objects >>>>>> are 'real'? and b) given the debates about ontologies in the >> world, >>>> do >>>>>> you think we can reach a consensus on what the base reality is? >>>>>> >>>>>> >>>>>>> >>>>>>> 2. You are commenting on the word modified. >>>>>>> If I crack the egg, >>>>>>> Y-> crack -> X >>>>>>> Y and X are IVPTs of egg >>>>>>> Y->X (we have a derivation) >>>>>>> >>>>>>> So looking at generation only, I feel it's OK to say the egg >>>> is >>>>>> modified, since >>>>>>> we >>>>>>> have now a new IVPT Y about the same egg. >>>>>>> >>>>>>> So, could you maybe make some suggestions on how you would revise >>>> the >>>>>>> definition? >>>>>> >>>>>> I'm not sure what point you're making about the cracking example, >>>> but >>>>>> I'd say generation is just a case where we are more >>>>>> familiar/comfortable with the thing produced by a process >> execution >>>> as >>>>>> a useful thing to discuss/track the provenance of, and potentially >>>>>> where the inputs of the process execution are uninteresting. A >>>> chicken >>>>>> lays an egg not because we can't talk about a set of atoms that >> the >>>>>> chicken rearranges into a state we want to identify as an egg but >>>>>> because that view is not very useful, so identifying the 'set of >>>> atoms >>>>>> in the chicken' that is used to produce the egg or the 'set of >>>> atoms' >>>>>> that exists before and after egg laying that comprise the egg >> after >>>>>> laying isn't useful and we record chicken controls eggLaying which >>>>>> generates egg. Both/all variant accounts are valid and consistent >> in >>>>>> the model I'm advocating, specifically egg does not change type >> from >>>>>> being a real object to a state of a set of atoms - 'set of atoms' >> is >>>> a >>>>>> real thing that has a stateful view corresponding to a real thing >>>>>> called an egg (an IVPT relation with egg). The fact that 99+% of >> us >>>>>> would just report generation of an egg and stop is OK (good in >> fact >>>> - >>>>>> we don't want to needlessly talk about alternate views any more >> than >>>>>> we should feel pressure to expand all processes into fine grained >>>>>> steps or include info about the movement of electrons in >> describing >>>>> computations). >>>>>> >>>>>> Thanks, >>>>>> >>>>>> Jim >>>>>>> >>>>>>> Thanks, >>>>>>> Luc >>>>>>> >>>>>>> >>>>>>> On 06/10/2011 02:28 PM, Myers, Jim wrote: >>>>>>>> >>>>>>>> >>>>>>>>> -----Original Message----- >>>>>>>>> From: Luc Moreau [mailto:L.Moreau@ecs.soton.ac.uk] >>>>>>>>> Sent: Friday, June 10, 2011 3:26 AM >>>>>>>>> To: Myers, Jim >>>>>>>>> Cc: public-prov-wg@w3c.org >>>>>>>>> Subject: Re: PROV-ISSUE-8: defining generation in terms of >> `IVPT >>>>>> of' >>>>>>>>> >>>>>>>>> Hi Jim, >>>>>>>>> >>>>>>>>> I had not seen your comment in line, my responses are also >>>> inline. >>>>>>>>> >>>>>>>>> On 10/06/11 02:28, Myers, Jim wrote: >>>>>>>>> >>>>>>>>>> This would mean that a heating process modifies an egg to >> create >>>> a >>>>>>>>>> >>>>>>>> warm egg, >>>>>>>> >>>>>>>>> it does not transform a cold egg into a warm egg? >>>>>>>>> >>>>>>>>>> Or do you mean both - a process execution can turn one thing >>>> into >>>>>>>>>> >>>>>>>> another, >>>>>>>> >>>>>>>>> these things can be considered IVPTs of a thing that >> participates >>>>>> in >>>>>>>>> >>>>>>>> the process >>>>>>>> >>>>>>>>> execution/ is modified by the process execution? And in an open >>>>>> world >>>>>>>>> assumption, a witness doesn't have to report the modified thing >>>> or >>>>>>>>> can >>>>>>>>> >>>>>>>> decline >>>>>>>> >>>>>>>>> to identify/report either of things in IVPT roles depending on >>>>>> their >>>>>>>>> >>>>>>>> ability to >>>>>>>> >>>>>>>>> observe and the use case they wish to enable? >>>>>>>>> >>>>>>>>>> ________________________________ >>>>>>>>>> >>>>>>>>>> From: public-prov-wg-request@w3.org on behalf of Luc Moreau >>>>>>>>>> Sent: Thu 6/9/2011 6:44 PM >>>>>>>>>> To: Provenance Working Group WG >>>>>>>>>> Subject: PROV-ISSUE-8: defining generation in terms of `IVPT >> of' >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Hi all, >>>>>>>>>> >>>>>>>>>> - if a new thing is created, it is clear that we have a new >> IVPT >>>>>> of >>>>>>>>>> that thing >>>>>>>>>> >>>>>>>>>> if a chicken creates an egg is it just an IVPT of an egg? >>>>>>>>>> >>>>>>>>>> >>>>>>>>> I would think the physical object is the egg. >>>>>>>>> I thought we had agreed that for a provenance purpose, we had >> to >>>>>> talk >>>>>>>>> >>>>>>>> about >>>>>>>> >>>>>>>>> an IVPT of that egg. >>>>>>>>> >>>>>>>> But 'the egg' is also an IVPT of the stuff that goes into the >> cake >>>> - >>>>>> a >>>>>>>> temporary 'state' in which yolk and white are together and not >>>>>>>> mixed/chemically altered, etc. >>>>>>>> >>>>>>>>> >>>>>>>>>> - if the thing is modified, then it is a requirement that a >> new >>>>>> view >>>>>>>>>> >>>>>>>> (IVPT) is >>>>>>>> >>>>>>>>> generated ... >>>>>>>>> >>>>>>>>>> otherwise, it would still be a view that existed before >>>>>>>>>> >>>>>>>>>> can't I say the egg was heated without reporting its cold and >>>> warm >>>>>>>>>> >>>>>>>> states? I.e. >>>>>>>> >>>>>>>>> don't we want to be able to report that something was modified >>>>>>>>> without >>>>>>>>> >>>>>>>> having >>>>>>>> >>>>>>>>> to report the IVPTs? A document was edited four times by >>>> different >>>>>>>>> >>>>>>>> people but I >>>>>>>> >>>>>>>>> don't wan't to/can't tell you what each wrote at each stage? >>>>>>>>> >>>>>>>>>> >>>>>>>>> These comments were made in the context of defining Generation >> of >>>>>> an >>>>>>>>> >>>>>>>> IVPT. >>>>>>>> >>>>>>>> OK - but you said "if the thing is modified"... For generation, >> I >>>>>>>> would say the chicken participates in an egg laying process >>>>>> execution >>>>>>>> that generates an 'egg'. That 'egg' is an IVPT of the chemicals >> in >>>>>> it >>>>>>>> (which existed before). The 'egg' can also have further/more >>>>>> stateful >>>>>>>> IVPTs that are more useful for discussing heating, cracking, >> etc. >>>>>> The >>>>>>>> sense in which generation is special is that it is a derivation >>>> from >>>>>>>> things we don't consider logically an aspect/IVPT of something >>>>>>>> greater. I.e. the 'mass of egg-bound chemicals' in the chicken >>>> just >>>>>>>> changes its state to become the 'egg', nothing really appears or >>>>>>>> disappears (conservation of mass and energy). Unless/until a >>>>>> scientist >>>>>>>> wants to look at the potential for different processing of >>>> chemicals >>>>>>>> going into the egg versus those used to build the chicken's own >>>>>> body, >>>>>>>> 'mass of egg-bound chemicals' isn't something we'd usually think >>>>>>>> about, but it's a valid perspective and consistent with the view >>>> of >>>>>> an >>>>>>>> egg being generated (both views can be drawn on the same graph >> in >>>>>> the >>>>>>> way I've been describing). >>>>>>>> >>>>>>>> >>>>>>>>> The document was edited four times could be expressed by 4 >>>> process >>>>>>>>> >>>>>>>> execution >>>>>>>> >>>>>>>>> and something like opm:wasTriggeredBy in between. >>>>>>>>> >>>>>>>>> >>>>>>>>>> - if the process execution was taking a long time to >>>> modify/create >>>>>>>>>> >>>>>>>> the thing, >>>>>>>> >>>>>>>>> there is only one >>>>>>>>> >>>>>>>>>> instant at which the (invariant!) IVPT appears >>>>>>>>>> >>>>>>>>>> I thnk we could define it that way, but if a cracking process >>>>>> takes >>>>>>>>>> >>>>>>>> time, saying >>>>>>>> >>>>>>>>> the cracked egg appears instantaneously basically means you >> want >>>>>>>>> >>>>>>>> 'cracked egg' >>>>>>>> >>>>>>>>> to be defined by some threshold - the cracked egg might become >>>> more >>>>>>>>> >>>>>>>> cracked >>>>>>>> >>>>>>>>> over time ) invariant only in that it is always above the >>>> threshold >>>>>>>>> >>>>>>>> and the >>>>>>>> >>>>>>>>> instance of the creation of the IVPT relationship occurs ata >>>>>>>>> >>>>>>>> aspecific instant. >>>>>>>> >>>>>>>>>> >>>>>>>>> Yes, agreed. >>>>>>>>> >>>>>>>>> >>>>>>>>>> - I think this captures well a stateful objects, where >> processes >>>>>> can >>>>>>>>>> >>>>>>>> modify the >>>>>>>> >>>>>>>>> object, resulting in >>>>>>>>> >>>>>>>>>> different IVPTs corresponding to the various states >>>>>>>>>> >>>>>>>>>> IVPTs are not a separate kind of thing and their invariance is >>>>>>>>>> >>>>>>>> relative. If they >>>>>>>> >>>>>>>>> are truly immutable sates/snapshopts, they can only exist for >> an >>>>>>>>> >>>>>>>> instant because >>>>>>>> >>>>>>>>> some part of the state of the thing (a part we may not care >> about >>>>>>>>> such >>>>>>>>> >>>>>>>> as age) >>>>>>>> >>>>>>>>> will change immediately. >>>>>>>>> >>>>>>>>>> >>>>>>>>> I am not sure I agree, here. IVPTs are a view/perspective on a >>>>>> thing. >>>>>>>>> >>>>>>>> Perhaps I should argue from the other direction - the notion of >> a >>>>>>>> thing is also a perspective/view. "eggs" don't exist - only >>>>>> temporary >>>>>>>> co-locations of particular molecules. Galton and Mizoguchi's >> paper >>>>>>>> argues that objects are defined by what processes you consider >> to >>>> be >>>>>>>> internal to and external to the object - if you change the set >> of >>>>>>>> processes you are concerned about, you describe the world using >>>>>>>> different objects. In this sense, eggs feel more 'real' because >>>> the >>>>>>>> set of processes we see happening frequently to them preserve >>>>>> aspects >>>>>>>> of their state, so egg as an IVPT is useful/predictive/etc. >>>>>>>> >>>>>>>>> Alternative views asserted by other asserters may co-exit. >>>>>>>>> - it's a decaying egg >>>>>>>>> - it's a duck egg, not a hen egg >>>>>>>>> - it's a chocolate egg >>>>>>>>> >>>>>>>>> >>>>>>>> I agree, so again from the other direction - I don't see why >> 'egg' >>>>>> is >>>>>>>> more real/more correct/more special than any of these, they're >> all >>>>>>>> IVPTs. >>>>>>>> >>>>>>>> >>>>>>>>> It is a requirement of any specific perspective to be >> invariant. >>>>>>>>> >>>>>>>> Invariant relative to a view in which only certain processes are >>>> of >>>>>>>> interest (are observable/reported?). >>>>>>>> >>>>>>>> >>>>>>>>> So, it's not a snapshot of the global egg state, but it's a >>>>>> snapshot >>>>>>>>> >>>>>>>> according to a >>>>>>>> >>>>>>>>> view. >>>>>>>>> >>>>>>>>> An analogy would be several cameras pointing to a same egg. >>>>>>>>> From one camera, the egg is still, no change occurring. >>>>>>>>> From the other, we see a crack appearing. >>>>>>>>> So one asserter can describe change in a physical object, while >>>>>>>>> >>>>>>>> another does not >>>>>>>> >>>>>>>>> describe any change. >>>>>>>>> But it's the same egg. >>>>>>>>> >>>>>>>> Right - those are two views of something. But that something is >>>> just >>>>>>>> another view - one camera sees a soup of chemicals that are >>>> swirling >>>>>>>> and mixing (slowly for an egg) while another sees one thing (the >>>>>> egg). >>>>>>>> Both of these are just IVPTs too. The chemical view is mutable >> by >>>>>> more >>>>>>>> processes than the egg view, but it is more persistent (it lasts >>>>>>>> longer because we've defined it in a way that the processes that >>>> can >>>>>>>> create/destroy it are less frequent). >>>>>>>> >>>>>>>> I know that thinking of everything as an IVPT is not necessarily >>>>>>>> intuitive, and that one can argue that it is just one way to >> model >>>>>> the >>>>>>>> world/a philosophy, but I think it is a model that has the right >>>>>>>> conceptual power to deal with the use cases we have (and the >>>> general >>>>>>>> set we can envision) while also being one that, in practice, >> will >>>>>> fade >>>>>>>> away >>>>>>>> - most people will agree that 'egg' and not 'mass of chemicals' >> is >>>> a >>>>>>>> more useful IVPT to talk about and we'll see 'eggs' used in cake >>>>>>>> baking and the world will mostly look like OPM (straight >>>>>>>> thing-execution-thing chains), but we'll still have the power to >>>>>> drop >>>>>>>> down and talk about cracking or go up and talk about >> conservation >>>> of >>>>>> mass >>>>>>> when needed. >>>>>>>> >>>>>>>> I also don't know what a coherent alternative is that, once we >> add >>>>>> in >>>>>>>> all the features necessary to cover the use cases, we'll like >>>>>> better. >>>>>>>> There are certainly other ways to model - my question really is >>>>>>>> whether there are others that will end up being more intuitive >>>> once >>>>>>>> all the needed features are dropped in. >>>>>>>> >>>>>>>> -- Jim >>>>>>>> >>>>>>>> Jim >>>>>>>> >>>>>>>>> Luc >>>>>>>>> >>>>>>>>>> What do you think? >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>> >>>>> >>> http://www.w3.org/2011/prov/wiki/ConceptGeneration#Definition_of_Gene >>>>>>>>> r >>>>>>>>> >>>>>>>>>> ation_by_Luc >>>>>>>>>> >>>>>>>>>> Cheers, >>>>>>>>>> Luc >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>> >>>>>>> -- >>>>>>> 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 Saturday, 11 June 2011 16:19:29 UTC