- From: Luc Moreau <l.moreau@ecs.soton.ac.uk>
- Date: Mon, 08 Oct 2012 14:14:13 +0100
- To: public-prov-wg@w3.org
- Message-ID: <EMEW3|d0d9d7da8c80d747a7c04cbea394eddeo97EEE08l.moreau|ecs.soton.ac.uk|5072D1A5>
Hi Robert, The only constraints that prov-constraints define for assocations appear at: http://www.w3.org/TR/2012/WD-prov-constraints-20120911/#wasAssociatedWith-ordering_text They require the agent and the activity to have some overlap. To model ithe examples you suggest, I would breakdown activities activity(ex:shift1) wasAssociatedWith(ex:shift1,ex:supervisor1) activity(ex:shift2) wasAssociatedWith(ex:shift2,ex:supervisor2) If your application requirement is stronger, and you need to be specific about the exact association time interval, then PROV does not offer you a solution. To understand the technical challenges associated with this, please wee answer related to prov:time in http://www.w3.org/2011/prov/wiki/ResponsesToPublicComments#ISSUE-530_.28attributes.29 Regards, Luc On 10/03/2012 07:37 PM, Freimuth, Robert, Ph.D. wrote: > Hi, > I'm trying to catch up on the flurry of PROV email over the last > week. The first two questions in this issue have been answered. I > would like clarification on the third. > Question: > > Can associations be valid for a window of time for a given activity? > For example, several agents are responsible for the activity of > preparing and serving food in a restaurant (server, cook, bartender), > but not all of them are responsible for the entire time the activity > is active. To support this, start and end times should be added to > Associations. > Response: > > PROV associations are not temporal relations. Instead, > prov-constraints define ordering constraints that are implied by > associations. The agent in an association is expected to have some > overlap with the activity. Likewise, for attribution, the agent exist > before this entity was generated. > Follow up: > How would PROV be used for the example above (preparing and serving > food)? In that case, three entities are responsible for specific > portions of an activity. Is there a way to say that a person acting as > a bartender was responsible for only a portion of the activity? > (Defining the association on the basis of role (e.g., cook vs. > bartender) seems straightforward, but the temporal aspect does not.) > A different example might involve oversight of (responsibility for) > the development of a widget (an activity). Supervisor A might > initiate the development process, but then transfer responsibility to > B at a shift change. If the widget is found to be defective, one > might look to the provenance of the widget's production to determine > who was responsible at a particular point in time. How is this > expressed with PROV? > If temporal relations are not supported, is it possible to detect > logical inconsistencies in provenance? Validating provenance > assertions is likely going to be a common use case, and I would expect > temporal validation to be heavily used. This is similar to temporal > restrictions on entities (e.g., cannot be used after it is terminated). > Thanks, > Bob > > ------------------------------------------------------------------------ > *From:* public-prov-wg-request@listhub.w3.org > [mailto:public-prov-wg-request@listhub.w3.org] *On Behalf Of *Luc > Moreau > *Sent:* Tuesday, September 25, 2012 8:27 AM > *To:* public-prov-wg@w3.org > *Subject:* Re: PROV-ISSUE-521: Data Model Section 5.3.3 [prov-dm] > > > Hi all, > > Find below a draft response to this issue, available on the wiki at: > http://www.w3.org/2011/prov/wiki/ResponsesToPublicComments#ISSUE-521_.28Responsibility_Activity.29 > > Feedback appreciated, > Regards, > Luc > > > ISSUE-521 (Responsibility Activity) > > * Original > email:http://lists.w3.org/Archives/Public/public-prov-wg/2012Sep/0111.html > > * Tracker:http://www.w3.org/2011/prov/track/issues/521 > * Group Response > o PROV agents bear responsibility for activities taking > place, entities being generated, and other agents. > o PROV agents MAY be entities or activities > o Given this, it is legal to write the following, in which > the type of a2 and a1 is inferred to be agent. > > activity(a1) > activity(a2) > actedOnBehalfOf(a2,a1) > > * > o The group has provided its answer to ISSUE-503 > o PROV associations are not temporal relations. Instead, > prov-constraints define ordering constraints that are > implied by associations. The agent in an association is > expected to have some overlap with the activity. Likewise, > for attribution, the agent exist before this entity was > generated. > o If an application, it is necessary to express that an > activity is associated with agent ag1 during interval > (evt1-evt2) and then with agent ag2 during interval > (evt2-evt3), the approach is to model this with two > activities, one for the first interval, or one for the > second interval. > * References: > o Type > inference:http://www.w3.org/TR/2012/WD-prov-constraints-20120911/#typing > > o Adopt plan > response:http://www.w3.org/2011/prov/wiki/ResponsesToPublicComments#ISSUE-503_.28adopt_plan.29 > > o Association ordering > constraints:http://www.w3.org/TR/2012/WD-prov-constraints-20120911/#wasAssociatedWith-ordering_text > > * Changes to the > document:http://dvcs.w3.org/hg/prov/rev/e89828e2a81c > * Original author's acknowledgement: > > > > On 10/09/2012 09:48, Provenance Working Group Issue Tracker wrote: >> PROV-ISSUE-521: Data Model Section 5.3.3 [prov-dm] >> >> http://www.w3.org/2011/prov/track/issues/521 >> >> Raised by: Luc Moreau >> On product: prov-dm >> >> >> http://www.w3.org/2011/prov/wiki/LC_Feedback#Data_Model_Section_5.3.3 >> >> ISSUE-463 >> >> By definition, agents can be both entities and activities (section 2.1.3). Can activities be responsible for other activities, or can only entities be assigned responsibility? >> >> Similarly, can activities adopt a plan when acting as an agent, or can only entity agents adopt plans? >> >> Can associations be valid for a window of time for a given activity? For example, several agents are responsible for the activity of preparing and serving food in a restaurant (server, cook, bartender), but not all of them are responsible for the entire time the activity is active. To support this, start and end times should be added to Associations. >> >> >> >> >> > > -- > 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 Kingdomhttp://www.ecs.soton.ac.uk/~lavm > -- 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 Monday, 8 October 2012 13:14:43 UTC