Re: Constraint V Refinement

I think we need to provide guidance on the difference.

Otherwise, different implementations may use deliveryChannel as an action refinement  in one Policy, then as a rule constraint in another.
(this would be good content for the Best Practices guide: https://w3c.github.io/odrl/bp/)

Can someone suggest improved definitions/clarifications for these:
  - A Rule MAY include the constraint property to indicate a condition on the Rule. 
  - An Action MAY include the refinement property to indicate a Constraint that narrows the semantics of the Action operation directly. 

Cheers - Renato


> On 8 Apr 2022, at 00:20, Víctor Rodríguez Doncel <vrodriguez@fi.upm.es> wrote:
> 
> Hi,
> 
> I do not see a great difference between refinement or constraint because its interpretation is not defined (cf. examples in a testbed where an algorithm must behave differently in each case), therefore the difference is only philosophical to me. And even in this case unclear: I would have said constraint, though, for the deliveryChannel, and if refinement, refinement of the action (this would be like an "adverb" modifying the action rather than an "adjective" qualifying the asset) 
> 
> Regards,
> Víctor
> 
> > Is the deliveryChannel a refinement on ‘stream’ or a constraint on the rule?
> 
> refinement on the asset i.e. the video itself? e.g., => "you can stream (action) videos whose deliveryChannel is YouTube (asset with deliveryChannel == YT)
> 
> br, simon
>> 
>> On Thu, 7 Apr 2022 at 02:42, Renato Iannella <r@iannel.la <mailto:r@iannel.la>> wrote:
>> 
>> Hi all, we generally define the constraint property as a “condition on the rule” and the refinement property as “narrow the semantics of the action”.
>> 
>> So, for example temporal and geospatial conditions apply to the rule, and printing at most 5 times is a refinement to print.
>> 
>> My question is how to interpret this difference with other use cases, such as:
>>  - you can stream (action) a video (asset)  on YouTube (deliveryChannel) only?
>> 
>> Is the deliveryChannel a refinement on ‘stream’ or a constraint on the rule?
>> 
>> Thanks…Renato
> 
> 
> -- 
> Víctor Rodríguez-Doncel
> D3205 - Ontology Engineering Group (OEG)
> Departamento de Inteligencia Artificial
> ETS de Ingenieros Informáticos
> Universidad Politécnica de Madrid
> 
> Campus de Montegancedo s/n
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