- From: Myers, Jim <MYERSJ4@rpi.edu>
- Date: Mon, 15 Aug 2011 15:02:54 +0000
- To: Graham Klyne <GK@ninebynine.org>
- CC: Simon Miles <simon.miles@kcl.ac.uk>, Provenance Working Group WG <public-prov-wg@w3.org>
PE - Process Execution. Simon has argued that they are just another type of entity (discussed in the emails he cited). Jim > -----Original Message----- > From: Graham Klyne [mailto:GK@ninebynine.org] > Sent: Monday, August 15, 2011 10:32 AM > To: Myers, Jim > Cc: Simon Miles; Provenance Working Group WG > Subject: Re: updates to PAQ doc for discussion > > Jim, > > What's a PE? Where did this term come from? In any case, I'm inclined to > resist a partitioning of the value space or resources into "entities" and > something else. > > Simon, > > I spotted your reference to owl:Thing. Not all provenance applications will > necessarily use OWL (even if OWL is used to define the semantics). My reading > of http://www.w3.org/TR/owl2-rdf-based-semantics/, particularly tables 4.1 > and 5.2, is that owl:Thing and rdf:Resource denote the same class of objects. > So it might be more generally applicable to developers to talk of rdf:Resource > rather than owl:Thing. > > #g > -- > > > Myers, Jim wrote: > > Simon, > > > > I probably should have said every resource is an entity or PE... :-) > > > > My statement about everything being an Entity in this thread was in the > context of the thing versus state of things debate which I think is the distinction > PAQ was making. Resource on the web that look mutable can be entities(live > web pages), resources that look frozen (a version of that page) can be entities, > entities made up for provenance purposes are clearly entities and could be > resources (they are not a different type just because they are only tracked for > provenance purposes). > > > > I would still argue that it will be clearer if we make Entities and PEs distinct, > rather than PE being a subtype of entity, and would just extend to say every > resource is an entity or PE to stay consistent. In analogy with the idea above, I > would argue that if there's a web resource that is an event, it qualifies as a PE > and we shouldn't need a target-like indirection mechanism to get to something > in the pil model. We may still want to describe sub-events, or entities that > participate in the event etc. that are not currently-existing resources, but the > original resource fits the model and the pil relationships are sufficient to relate > everything. > > > > The discussion in [1] is from a different angle, but I think it is > > still consistent. That one was discussing avoiding things like > > functions being required to determine identity, e.g. for Java object > > instances. The point there was to avoid situations in which PIL/PAQ > > had to be aware of functions or other mechanisms to allow discovery > > and I think I was basically arguing that one should do something like > > what the resource mechanism does - in the semantic web sense a > > resource with a URI represents something in the world and limits what > > you can retrieve about that thing to content and metadata. For > > example, content size is really a function of the content, but is > > presented as metadata. pil:entity should work like that. If it does, I > > don't see any technical reason why a resource can't have metadata you > > want for an entity or vice versa how you could create an entity that > > would not be a viable resource. As before, this doesn't say that there > > aren't social/practical reasons that som > eone owning a URL refuses to serve metadata, or that all entities will be things > one wants to serve as resources. So indirection to/from existing resources in > the world is useful, but, if you agree that the resources you want to map to > pil:entities are also valid entities, a target-URI type mechanism now has a > domain and range of pil:entity and we should be asking if target is a sub-type of > IVPof, derivation, etc. versus a new concept coming in through PAQ. (If we're > talking about things without a URI, I think I;m just arguing to use the semantic > web notion of representing it with a resource and using that as the pil:entity, > versus having a PIL-specific mechanism.) > > > > I hope that makes sense - I still feel like things are self-consistent... > > > > Jim > > > > > > ________________________________________ > > From: public-prov-wg-request@w3.org [public-prov-wg-request@w3.org] on > > behalf of Simon Miles [simon.miles@kcl.ac.uk] > > Sent: Sunday, August 14, 2011 6:59 AM > > To: Provenance Working Group WG > > Subject: Re: updates to PAQ doc for discussion > > > > Hello Paul, Jim, all, > > > > Jim: > >> I think everything is a pil:Entity! > > > > I am in favour of this view, but I didn't think you were... If it is > > true, doesn't it mean that, in the formal model, any distinction > > between pil:Entity and owl:Thing is misleading, and so one should be > > mapped to the other? I had the (possibly mistaken) impression from > > other discussions [1, 2] that you disagreed with the consequences of > > this and so a pil:Entity had something special about it. In which > > case, Paul may argue that some resources may not have these special > > characteristics and we need separate "targets". I'm happy to go with > > what the group agrees, but I don't think the definition of entity in > > the model expresses how general a class Entity is, which appears to > > have consequences for the PAQ. > > > > Paul: > >> I still think there's a case for allowing a target-uri to be specified when you > don't want to put the URL of the resource in the provenance. For example, > many sites have long urls for implementation purposes but may want to > describe provenance in terms of a "better" URL e.g. A permalink. > > > > I agree this is an important reason for having the target URI > > (somewhere) - even if a resource itself is an entity and ivpOf > > relations can be expressed in the provenance data, the identifiers > > that clients have for it may not be the ones used in provenance for > > whatever reasons, or the client may not have an identifier at all, as > > discussed in issue 46 [3] > > > > thanks, > > Simon > > > > [1] > > http://lists.w3.org/Archives/Public/public-prov-wg/2011Jul/0111.html > > [2] > > http://lists.w3.org/Archives/Public/public-prov-wg/2011Aug/0017.html > > [3] http://www.w3.org/2011/prov/track/issues/46 > > > > > >> At any rate, I think this is a better way to describe the PAQ without getting > involved in the model. > >> > >> We'll see what Graham and others think. > >> > >> Cheers > >> Paul > >> > >> On Aug 12, 2011, at 15:32, "Myers, Jim" <MYERSJ4@rpi.edu> wrote: > >> > >>> Paul, > >>> > >>> I think everything is a pil:Entity! Nominally a living page could > >>> have direct provenance - when did it first appear, who approved it > >>> getting added to the overall site, when did it get downloaded, used > >>> in a backup process, etc. Just because we have an open world and we > >>> (some asserter) may not have provenance to directly associate with > >>> it doesn't mean it is not/can't be a pil:Entity. To look at it > >>> backwards, if IVPOf fits the need, why would you not want to > >>> consider the living page to be a pil:Entity. > >>> > >>> With everything being able to be a pil:Entity, I think in the > >>> following > >>> way: For resource X, if I want to talk about aspects of it that are > >>> immutable, I directly associate provenance statements with it via > >>> used, generatedby, derived. If I want to talk about its mutable > >>> aspects, I create additional characterizations (e.g. versions for > >>> content) - additional pil:Entitities that may also already be > >>> resources themselves or may just be being invented/defined for > >>> provenance purposes (e.g. if I am not already tracking versions of > >>> my live page as part of my site operations, I identify them just for > >>> provenance purposes so I can talk about when each version was > >>> created, read, etc.) and associate them with the original via IVPof > >>> relationships and then use used/generatedby on the > >>> characterizations. If X is really just the context or is controlling some other > process we have agent and participation. > >>> > >>> Jim > >>> > >>>> -----Original Message----- > >>>> From: Paul Groth [mailto:pgroth@gmail.com] On Behalf Of Paul Groth > >>>> Sent: Friday, August 12, 2011 2:13 AM > >>>> To: Myers, Jim > >>>> Cc: Khalid Belhajjame; public-prov-wg@w3.org > >>>> Subject: Re: updates to PAQ doc for discussion > >>>> > >>>> Hi Jim, > >>>> > >>>> "the targetURI discussion is about relating the living page to its > >>> versions which > >>>> then have provenance" > >>>> > >>>> that's a fairly good summary. > >>>> > >>>> Can you clarify that Complement Of (was IVPof) works on things that > >>> are not > >>>> pil:Entities? I thought it only applies to pil:Entity? > >>>> > >>>> thanks, > >>>> Paul > >>>> > >>>> > >>>> > >>>> > >>>> Myers, Jim wrote: > >>>>>> Now, if one says that every resource is a pil:Entity, we may not > >>>>>> need > >>>>> this > >>>>> > >>>>> That, or that every pil:Entity can be a resource (or both). As > >>> before > >>>>> if I have a living web page with some URL, it may have different > >>>>> versions that have different (but related) provenance. If I > >>> understand > >>>>> correctly, the targetURI discussion is about relating the living > >>> page > >>>>> to its versions which then have provenance (it also makes the > >>>>> assumption that there are resources that don't have any direct > >>>>> provenance - all the provenance is associated with versions or > >>>>> other things that are IVPsOf the resource). I'm pointing out that > >>>>> each version is a valid web resource as well (could be given its > >>>>> own URI) so we don't have to treat it as a different class of > >>>>> thing, and that just because we don't have direct provenance for a > >>>>> resource doesn't mean it isn't a valid pil:entity. > >>>>> > >>>>> With the IVPof relation, we still have the mechanism to relate the > >>>>> version resources with the living webpage resource, so we don't > >>>>> lose any expressivity from what's in the PAQ doc. I think it just > >>>>> shifts the discussion from targets as a separate type to PIL > >>>>> describing the provenance of resources and having the capability > >>>>> to capture the situation where some/all of the known provenance is > >>>>> associated with specific version resources or other types of > >>>>> resources that > >>> partially > >>>>> characterize the resource. > >>>>> > >>>>> Jim > >>>>> > >>>>>> -----Original Message----- > >>>>>> From: Paul Groth [mailto:pgroth@gmail.com] On Behalf Of Paul > >>>>>> Groth > >>>>>> Sent: Thursday, August 11, 2011 2:01 PM > >>>>>> To: Myers, Jim > >>>>>> Cc: Khalid Belhajjame; public-prov-wg@w3.org > >>>>>> Subject: Re: updates to PAQ doc for discussion > >>>>>> > >>>>>> Hi Jim, Khalid: > >>>>>> > >>>>>> In the model, provenance is described with respect to pil:Entities. > >>>>>> In > >>>>> the PAQ > >>>>>> document, we describe access primarily with respect to the Web > >>>>> Architecture. > >>>>>> It may be the case that the resource (e.g. a web page) is a > >>>>> pil:Entity. If so, then > >>>>>> the access approach says go ahead and use the url of that > >>>>>> resource > >>> to > >>>>> find the > >>>>>> provenance of it within an identified set of provenance > >>> information. > >>>>>> However, it may be the case that the resource is not a pil:Entity. > >>> In > >>>>> that case, > >>>>>> we provide a mechanism (Target-URIs) that let you associate the > >>>>> resource to a > >>>>>> pil:Entity (the target) such that you can identify a > >>> characterization > >>>>> of the > >>>>>> resource and thus find it in some provenance provenance > >>> information. > >>>>>> This approach also lets you have multiple pil:Entities associated > >>>>>> with > >>>>> a > >>>>>> particular resource. > >>>>>> > >>>>>> We are just rying to find a simple way to let the accessor know > >>> when > >>>>> they get > >>>>>> some provenance information what they should be looking for > >>>>>> within > >>>>> that > >>>>>> provenance information. > >>>>>> > >>>>>> Now, if one says that every resource is a pil:Entity, we may not > >>>>>> need > >>>>> this. Is > >>>>>> that what you're saying? and can you explain how this is the case? > >>>>>> > >>>>>> I hope this clarifies what we are trying to enable. > >>>>>> > >>>>>> Paul > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>>>> > >>>>>> Myers, Jim wrote: > >>>>>>> I think the gist of the discussion on the modeling side lately > >>>>>>> and > >>>>> the > >>>>>>> decision to have 'only Bobs' would shift this towards just > >>>>>>> talking about the link between provenance and resources with the > >>>>>>> model > >>> then > >>>>>>> having a mechanism to indicate when some resources are views of > >>>>>>> others, i.e. one URI is the page content on a given date and the > >>>>> other > >>>>>>> URI is the live page, but both are resources that can have > >>>>> provenance, > >>>>>>> and their provenance can contain links that indicate their > >>>>> relationship. > >>>>>>> Jim > >>>>>>> > >>>>>>> *From:*public-prov-wg-request@w3.org > >>>>>>> [mailto:public-prov-wg-request@w3.org] *On Behalf Of *Khalid > >>>>>>> Belhajjame > >>>>>>> *Sent:* Thursday, August 11, 2011 10:13 AM > >>>>>>> *To:* Paul Groth > >>>>>>> *Cc:* public-prov-wg@w3.org > >>>>>>> *Subject:* Re: updates to PAQ doc for discussion > >>>>>>> > >>>>>>> Hi, > >>>>>>> > >>>>>>> My main concern reading sections 1 and 3, is the use of both > >>>>> resource > >>>>>>> and target entity. I understand that the idea is that a web > >>>>> resources > >>>>>>> may be associated with multiple target entities, and that there > >>>>>>> is > >>> a > >>>>>>> need to identify which target the provenance describes. However, > >>>>>>> having to go through the two levels resource then entity is a > >>>>>>> bit confusing, specially for a reader is not aware of the > >>>>>>> discussions > >>>>> that > >>>>>>> we had about the two concepts. > >>>>>>> > >>>>>>> Suggestion: Would it be really bad if we confine ourselves to > >>>>>>> the provenance vocabulary and describe how the provenance of an > >>> Entity, > >>>>> as > >>>>>>> opposed to a resource, can be accessed? > >>>>>>> > >>>>>>> Other comments: > >>>>>>> > >>>>>>> - In the definition of a resource, it said that "a resource may > >>>>>>> be associated with multiple targets". It would be good if we > >>>>>>> could clarify this relationship a bit more. > >>>>>>> > >>>>>>> - I find the definition of provenance information a bit vague, > >>>>>>> the body of the definition says pretty much the same thing as > >>>>>>> the > >>> title > >>>>> of > >>>>>>> the definition. If we don't have a better idea of what can be > >>> said, > >>>>> it > >>>>>>> is probably better to remove it. > >>>>>>> > >>>>>>> In Section 3, Second paragraph, "Once provenance information > >>>>>>> information" -> "once provenance information" > >>>>>>> > >>>>>>> In the same paragraph: "one needs how to identify" -> "one > >>>>>>> needs > >>> to > >>>>>>> know how to identify". > >>>>>>> > >>>>>>> Khalid > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>> > >>>>>>> On 10/08/2011 20:37, Paul Groth wrote: > >>>>>>> > >>>>>>> Hi All, > >>>>>>> > >>>>>>> Graham and I have been making some changes to the PAQ document > >>>>>>> [1] that we would like to request feedback on at tomorrow's telecon. > >>>>>>> > >>>>>>> In particular, we have updated Sections 1 and 3. We've added a > >>>>> section > >>>>>>> on core concepts and made section 3 reflect these concepts. We > >>> think > >>>>>>> this may address PROV-ISSUE-46 [2]. > >>>>>>> > >>>>>>> Please take a look and let us know what you think. > >>>>>>> > >>>>>>> Thanks, > >>>>>>> Paul > >>>>>>> > >>>>>>> Note: Section 4 Provenance discovery service is still under > >>>>>>> heavy editing > >>>>>>> > >>>>>>> > >>>>>>> [1] > >>>>>>> > >>> http://dvcs.w3.org/hg/prov/raw-file/default/paq/provenance-access.ht > >>> ml > >>>>>>> [2] http://www.w3.org/2011/prov/track/issues/46 > >>>>>>> > >>>>>> -- > >>>>>> Dr. Paul Groth (p.t.groth@vu.nl) > >>>>>> http://www.few.vu.nl/~pgroth/ > >>>>>> Assistant Professor > >>>>>> Knowledge Representation& Reasoning Group Artificial > >>>>>> Intelligence Section Department of Computer Science VU University > >>>>>> Amsterdam > >>>> -- > >>>> Dr. Paul Groth (p.t.groth@vu.nl) > >>>> http://www.few.vu.nl/~pgroth/ > >>>> Assistant Professor > >>>> Knowledge Representation & Reasoning Group Artificial Intelligence > >>> Section > >>>> Department of Computer Science VU University Amsterdam > >> > >> > ________________________________________________________________ > _____ > >> _ 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 > > > > > >
Received on Monday, 15 August 2011 15:03:33 UTC