- From: Graham Klyne <graham.klyne@zoo.ox.ac.uk>
- Date: Wed, 30 May 2012 09:52:29 +0100
- To: public-prov-wg@w3.org
On 29/05/2012 22:37, Luc Moreau wrote: > Hi Tim, Stephan, Graham, > > So, you are all defending role, as an alternative way of specializing relations. > OK. > > So, we now need to agree: > 1. on the domain of prov:hadRole By domain here, I assume you mean the relations for which it may be an attribute. The easy answer would be "all of them". > 2. on a definition of role that works with this domain > > Currently: we have: > /A role is the function of an entity with respect to an activity, in the context > of a usage, generation, association, start, and end./ Yes, the wordsmithing could be tricky if it is to preserve the intuitions. Technically, I think it's just introducing a subrelation of the relation to which it is applied. (So if a binary relation is a set of pairs, its a subset of those pairs, similarly for N-way relations). > We seem to be in agreement that we want roles also for > - invalidation Consistency and uniformity would suggest so, though in this case I'm not sure what the intuition would be. > The current definition works for: usage, generation, start, end, invalidation. > > This definition: > > /A role is the function of an entity or an *agent* with respect to an activity > > /would also work for association. > > It's not clear this definition would work for: > - delegation > actedOnBehalfOf(ag2,ag1,a) > a role for which agent ? responsible? delegate? I think it's not so far off - it would presumably be some subset of the roles that ag1 has with respect to a that are being delegated? > - attribution > no activity here. I think the notion of role works here: e.g. you etal are attributed as editors of PROV-DM, several more of us are attributed as authors. > - communication? > wasInformedBy(a2,a1) here no entity Again, I think it could apply here. As a student, my writing of an essay would be informed by my learning of material; as a miscreant, my writing of a penance piece (remember "lines"?) could be informed by my misdeed. I think "student" and "miscreant" stand here as roles. > - derivation? > wasDerivedFrom(e2,e1,a,g,u) > a role for which entity? Neither, or both. The role designates a relationship between the entities, not about one of them in isolation. > So, I would propose: > /A role is the function of an entity or an *agent* with respect to an activity,/ > /in the context of a usage, generation, association, start, end, and invalidation. > /For all these relations, an activity is subject or object. My inclination would be to start from a simple technical definition that can apply to all relationships, and then to illustrate it with a series of examples, rather than to try and capture all the (sometimes diverse) intuitions in the definition. #g -- > On 29/05/12 18:29, Graham Klyne wrote: >> On 29/05/2012 17:02, Luc Moreau wrote: >>> Hi Tim and Paul, >>> >>> We should also add it to Invalidation (because there is an activity). >>> >>> So, it looks like, if we follow Tim's suggestion, roles would be >>> allowed on all qualified relations, except Derivation and Communication. >>> Why not these now? >>> >>> This brings up a question: /what is the difference between prov:role and >>> prov:type?/ >> >> I think it's similar to the difference (in RDF) between subClass and >> subProperty, or class and property). >> >> (In the RDF formal semantics, they actually look very similar - properties >> have 2-part relational extensions, and types have single-value extensions. >> Several years ago, Peter Patel-Schneider proposed an alternative semantic >> model over the underlying RDF/XML structure that unified these.) >> >> But I think to try and unify them in PROV-DM would cause more head-scratching >> than it would save - I think the notions of type and role carry some useful >> intuition which may be good to keep. (Noting that roles in PROV-DM may be >> 2-way and sometimes multi-way relations.) >> >> #g >> -- >> >> >>> These are examples of prov:role in prov-dm. >>> >>> wasAssociatedWith(ex:edit1, ex:Paolo, -, [ prov:role="editor" ]) >>> wasAssociatedWith(ex:edit1, ex:Simon, -, [ prov:role="contributor" ]) >>> wasAttributedTo(tr:WD-prov-dm-20111215, ex:Paolo, [ prov:role="editor" ]) >>> wasAttributedTo(tr:WD-prov-dm-20111215, ex:Simon, [ prov:role="contributor" ]) >>> wasAssociatedWith(ex:a, ex:ag1, -, [ prov:role="loggedInUser", >>> ex:how="webapp" ]) >>> wasAssociatedWith(ex:a, ex:ag2, ex:wf, [ prov:role="designer", >>> ex:context="project1" ]) >>> wasAssociatedWith(a, ag1, [ prov:role="loggedInUser" ]) >>> wasAssociatedWith(a, ag, [ prov:role="operator" ]) >>> used(ex:div01, ex:cell, [ prov:role="divisor" ]) >>> >>> They could have been written as (Sorry for the sometime poor choice of name, but >>> you should get >>> the idea) >>> >>> wasAssociatedWith(ex:edit1, ex:Paolo, -, [ >>> prov:type="WasAssociatedWithAsEditor" ]) >>> wasAssociatedWith(ex:edit1, ex:Simon, -, [ >>> prov:type="WasAssociatedWithAsContributor" ]) >>> wasAttributedTo(tr:WD-prov-dm-20111215, ex:Paolo, [ >>> prov:type="WasAttributedToEditorEditor" ]) >>> wasAttributedTo(tr:WD-prov-dm-20111215, ex:Simon, [ >>> prov:type="WasAttributedToEditorContributor" ]) >>> wasAssociatedWith(ex:a, ex:ag1, -, [ >>> prov:type="WasAssociatedWithAsLoggedInUser", ex:how="webapp" ]) >>> wasAssociatedWith(ex:a, ex:ag2, ex:wf, [ >>> prov:type="WasAssociatedWithAsDesigner", ex:context="project1" ]) >>> wasAssociatedWith(a, ag1, [ prov:type="WasAssociatedWithAsLoggedInUser" ]) >>> wasAssociatedWith(a, ag, [ prov:type="WasAssociatedWithAsOperator" ]) >>> used(ex:div01, ex:cell, [ prov:type="UsedAsDivisor" ]) >>> >>> It feels that all role information can be expressed as type. >>> >>> So, >>> 1. when should we encode this kind of information with prov:type and when should >>> do with prov:role. >>> 2. what distinguishes prov:role from prov:type? >>> 3. what's the definition of prov:role >>> 4. should we drop prov:role, and just use prov:type? >>> >>> Luc >>> >>> >>> On 05/29/2012 02:54 PM, Timothy Lebo wrote: >>>> Currently, only Association (or Start, End, Usage, Generation) may use hadRole. >>>> >>>> Looking back, I see that one of the prov-o examples violates this: >>>> https://dvcs.w3.org/hg/prov/raw-file/default/ontology/Overview.html#qualifiedResponsibility >>>> >>>> >>>> by putting a role on a Delegation. >>>> >>>> >>>> Association, Attribution, and Delegation are the three ways to ascribe >>>> responsibility. >>>> >>>> May we relax hadRole and permit its use on Attribution and Delegation? >>>> >>>> (so, for this issue, +1; and a new issue to add it to Delegation, too :) >>>> >>>> -Tim >>>> >>>> >>>> On May 26, 2012, at 5:48 AM, Paul Groth wrote: >>>> >>>>> Hi Luc, >>>>> >>>>> It's unclear to me if attribution has an underlying activity. If we >>>>> agree on that then the definition falls out and we should could use >>>>> prov:role with respect to activity. >>>>> >>>>> I guess the argument could be that there is always an activity that >>>>> links the agent to an entity in the end. Is that what we say in the >>>>> end? >>>>> >>>>> Thanks >>>>> Paul >>>>> >>>>> On Thu, May 24, 2012 at 11:14 PM, Provenance Working Group Issue >>>>> Tracker<sysbot+tracker@w3.org> wrote: >>>>>> PROV-ISSUE-384 (prov-role-in-attribution): prov:role in attribution or not? >>>>>> [prov-dm] >>>>>> >>>>>> http://www.w3.org/2011/prov/track/issues/384 >>>>>> >>>>>> Raised by: Luc Moreau >>>>>> On product: prov-dm >>>>>> >>>>>> >>>>>> In the example, >>>>>> http://www.w3.org/TR/prov-dm/#anexample-attribution, >>>>>> we write: >>>>>> wasAttributedTo(tr:WD-prov-dm-20111215, ex:Paolo, [prov:role="editor"]) >>>>>> >>>>>> >>>>>> But in >>>>>> http://www.w3.org/TR/prov-dm/#term-attribute-role >>>>>> we say: >>>>>> The attribute prov:role denotes the function of an entity with respect to an >>>>>> activity, in the context of a usage, generation, association, start, and end. >>>>>> >>>>>> >>>>>> So, >>>>>> 1. Do we want to accept prov:role in Attribution? >>>>>> (or, it's not a prov:role but prov:type we should use?) >>>>>> >>>>>> 2. If yes, does it mean the definition of prov:role needs to be changed? >>>>>> where is the activity? >>>>>> >>>>>> 3. Should we have an optional activity in Attribution? >>>>>> >>>>>> Luc >>>>>> >>>>>> >>>>>> >>>>> >>>>> >>>>> -- >>>>> -- >>>>> 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 >>>>> >>>>> >>>> >>> >> >
Received on Wednesday, 30 May 2012 09:00:49 UTC