W3C home > Mailing lists > Public > public-prov-wg@w3.org > May 2012

Re: [provo] Difference between wasInformedBy and wasStartedByActivity (ttl examples)

From: Timothy Lebo <lebot@rpi.edu>
Date: Tue, 8 May 2012 19:12:37 -0400
Cc: Luc Moreau <L.Moreau@ecs.soton.ac.uk>, "public-prov-wg@w3.org" <public-prov-wg@w3.org>
Message-Id: <7AB2519E-C1DF-4338-8FFA-C9C1210E6DD3@rpi.edu>
To: Daniel Garijo <dgarijo@delicias.dia.fi.upm.es>

On May 8, 2012, at 6:03 PM, Daniel Garijo wrote:

> Hi Luc, Tim.
> One question: what would be the domain of the unqualified wasStartedBy relationship?

Activity

(but do you mean to ask about the range of wasStartedBy?)


> (talking form the RDF PROV-O perspective, not the DM. The DM new draft looks good to me).
> 
> Would it be (Entity U Activity) or just Entity?

The range of wasStartedBy would be just Entity, and the qualification (Start) would be EntityInvolvement.


> In order to support "identifier (a1) for the activity 
> that generated the (possibly unspecified) entity (e)" it should be the former, right?.

prov:hadActivity would reference a1 on the instance of Start.

:foot_race
   a prov:Activity;
   prov:wasStartedBy :bang;
   prov:qualifiedStart [
        a prov:Start;
         prov:hadActivity :firing_of_pistol;
    ];

A consequence of this is that if one wants to cite the activity and does not care about the Entity (trigger), they must use the extra qualification modeling.
i.e., one cannot say :foot_race prov:wasStartedBy :firing_of_pistol .

-Tim



> 
> Thanks,
> Daniel
> 
> 2012/5/8 Luc Moreau <L.Moreau@ecs.soton.ac.uk>
> Hi Tim,
> Yes, it would remain EntityInvolvement, with optional hadActivity.
> Luc
> 
> Professor Luc Moreau
> Electronics and Computer Science
> University of Southampton 
> Southampton SO17 1BJ
> United Kingdom
> 
> On 8 May 2012, at 22:48, "Timothy Lebo" <lebot@rpi.edu> wrote:
> 
>> Luc,
>> 
>> I like how either an Entity or Activity can be optional in a Start. It seems flexible for the variety of perspectives one may have or want to take.
>> 
>> Would Start always be a EntityInvolvement with an optional hadActivity?
>> I am comfortable with this, since regardless of whether you name/describe the entity, the trigger was involved.
>> 
>> +1 to the new draft. It seems to resolve my concerns.
>> 
>> Regards,
>> Tim
>> 
>> 
>> 
>> On May 8, 2012, at 5:24 PM, Luc Moreau wrote:
>> 
>>> Hi Stian, Paolo, all,
>>> 
>>> I have encoded the proposal 
>>> https://dvcs.w3.org/hg/prov/raw-file/31e2dc0de82d/model/working-copy/wd6-wasStartedBy.html
>>> 
>>> If people are happy, we can then adjust wasEndedBy similarly.
>>> I propose to take a vote on this on Thursday.
>>> 
>>> Luc
>>> 
>>> On 08/05/12 17:06, Stian Soiland-Reyes wrote:
>>>> 
>>>> That dual-mode style would confuse the interpretation of wasStartedBy, the activity becomes a token (and thus and entity)
>>>> 
>>>> Perhaps better would be to add the activity as an optional parameter to wasStartedBy in dm and add prov:hadActivity/prov:startedByActivity to prov:Start. It would mirror the activity of derivations.
>>>> 
>>>> An activity start, written wasStartedBy(id,a,e,t,a2, attrs) in PROV-N, has:
>>>> 
>>>> id: an OPTIONAL identifier for the activity start;
>>>> (..)
>>>> activity: an OPTIONAL activity (a2) which generated the (possibly unspecified) entity (e)
>>>> 
>>>> attributes: an OPTIONAL set (attrs)of attribute-value pairs representing additional information about this activity start.
>>>> 
>>>> Then mirror this for wasEndedBy.
>>>> 
>>>> -- 
>>>> Stian Soiland-Reyes, myGrid team
>>>> School of Computer Science
>>>> The University of Manchester
>>>> 
>>>> On May 8, 2012 3:03 PM, "Daniel Garijo" <dgarijo@delicias.dia.fi.upm.es> wrote:
>>>> Hi Stian,
>>>> instead of removing the constraint that entity and activity are disjoint we could
>>>> also (as another possibility) have activities OR entities as possible domain
>>>> of wasStartedBy. Now that we agreed on having an OWL-RL ++ profile,
>>>> this would be possible.
>>>> 
>>>> Thus, we would drop wasStartedByActivity, since wasStartedBy would
>>>> cover already the desired functionality, right? 
>>>> 
>>>> Thanks,
>>>> Daniel
>>>> 
>>>> 2012/5/8 Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
>>>> On Mon, May 7, 2012 at 3:48 PM, Timothy Lebo <lebot@rpi.edu> wrote:
>>>> 
>>>> > +1, repositioning wasStartedByActivity as a "blurrier" form of wasStartedBy seems to finally find a place for it in the model.
>>>> > Though, like Khalid, I'm not sure it will be used much, or correctly.
>>>> 
>>>> It will certainly still be confusing, as it was for me. As you said,
>>>> most wasStartedBy() would also come with a twin used() relationship
>>>> (and therefore imply a wasInformedBy() relation).   At some point
>>>> wasStartedBy was sub-property of wasInformedBy (making the choice
>>>> simple) - but not anymore.
>>>> 
>>>> As Luc raised, why not also wasEndedByActivity,  wasStartedByAgent etc.?
>>>> 
>>>> 
>>>> So it might just not be worth it to keep wasStartedByActivity(). It's
>>>> a bad sign if it's confusing to even the ontology designers, then how
>>>> is any meaningful provenance exchange happen, where one party apply
>>>> wasInformedBy like wasStartedByActivity, and the other the opposite?
>>>> 
>>>> 
>>>> 
>>>> A second solution would be to remove the constraint that activity and
>>>> entity are disjoint. Then you could say wasStartedBy(a2, a1),
>>>> wasEndedBy(a2, a3) etc. - the activity can play the role of an entity
>>>> as well, rather than inventing invisible phantom token entities. We
>>>> are talking blurry provenance here, right, we don't know quite the
>>>> nature of the interaction.
>>>> 
>>>> 
>>>> 
>>>> > How can it be reframed so that wasStartedByActivity can "grow" in details like Derivation does with hadActivity, hadUsage, and hadGeneration?
>>>> 
>>>> By adding a separate wasStartedBy() I would believe you have given all
>>>> the information (as an activity can only be started once).  Or is it
>>>> allowed to be wasStartedBy() two or more entities..? Luc?
>>>> 
>>>> 
>>>> --
>>>> Stian Soiland-Reyes, myGrid team
>>>> School of Computer Science
>>>> The University of Manchester
>>>> 
>>>> 
>> 
> 
Received on Tuesday, 8 May 2012 23:22:48 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 8 May 2012 23:22:50 GMT