Re: PROV-ISSUE-239 (TLebo): is wasGeneratedBy(e) meaningful? [prov-dm]

Tim

what I meant is that the def. should not make it optional.

wasGeneratedBy([],e) seems uninformative.

The argument that you could have a timestamp brings us back to the F2F discussion on separating "at" from "by" everywhere:

wasGeneratedAt(), wasGeneratedB(),
wasStartedAt(), wasStartedBy()
...

-Paolo


  On 2/7/12 1:20 AM, Timothy Lebo wrote:
> /
> /
>
>
>
> On Feb 6, 2012, at 5:57 PM, Paolo Missier wrote:
>
>> The activity should not be optional, surely?
>
> But it is!
>
>
> All of the components except entity are optional, so DM lets me say "wasGeneratedBy(e)"
> /wasGeneratedBy(id,e,a,t,attrs)/
>
>   * /id/: an /optional/ identifier id identifying the generation record;
>   * /entity/: an identifier e identifying an entity record that represents the entity that is created;
>   * /activity/: an /optional/ identifier a identifying an activity record that represents the activity that creates the entity;
>   * /time/: an /optional/ "generation time" t, the time at which the entity was created;
>   * /attributes/: an /optional/ set of attribute-value pairs attrs that describes the modalities of generation of this entity by
>     this activity.
>
>
> so the activity _must_ be there, and if it's not named then we _must_ name one?
>
> If so, then how do we tell the difference between that kind of optional and the truly optional references?
>
>
>
> -Tim
>
>
>
>
>>
>> -Paolo
>>
>> On 2/6/12 9:19 PM, Provenance Working Group Issue Tracker wrote:
>>> PROV-ISSUE-239 (TLebo): is wasGeneratedBy(e) meaningful? [prov-dm]
>>>
>>> http://www.w3.org/2011/prov/track/issues/239
>>>
>>> Raised by: Timothy Lebo
>>> On product: prov-dm
>>>
>>> Everything but entity is OPTIONAL in wasGeneratedBy.
>>>
>>> If I say only wasGeneratedBy(e), what did I say? And why was I allowed to say it?
>>>
>>> from WD3:
>>>
>>>
>>> A generation record, written wasGeneratedBy(id,e,a,t,attrs) in PROV-ASN, has the following components:
>>>
>>>     id: an optional identifier id identifying the generation record;
>>>     entity: an identifier e identifying an entity record that represents the entity that is created;
>>>     activity: an optional identifier a identifying an activity record that represents the activity that creates the entity;
>>>
>>>
>>>
>>
>>
>> -- 
>> -----------  ~oo~  --------------
>> Paolo Missier - Paolo.Missier@newcastle.ac.uk <mailto:Paolo.Missier@newcastle.ac.uk>, pmissier@acm.org <mailto:pmissier@acm.org>
>> School of Computing Science, Newcastle University,  UK
>> http://www.cs.ncl.ac.uk/people/Paolo.Missier
>>
>>
>>
>


-- 
-----------  ~oo~  --------------
Paolo Missier - Paolo.Missier@newcastle.ac.uk, pmissier@acm.org
School of Computing Science, Newcastle University,  UK
http://www.cs.ncl.ac.uk/people/Paolo.Missier