Re: Constraint V Refinement

Hi!

> So, is “streaming on Youtube” narrower semantics than just “streaming”?

I would say so, yes. e.g., becoming affiliated with twitch.tv as a streamer
contains following context exclusivity clause:
https://www.twitch.tv/p/en/legal/affiliate-agreement/#:~:text=Twitch%20has%20the%20exclusive%20right,%E2%80%9CChannel%20Subscription%20Services%E2%80%9D
)

"Twitch has the exclusive right to offer, promote and make available your
User Content, in which such User Content has not been bundled with any
third-party content, to end users and viewers of the Twitch Services on a
subscription, pay-per-view or similar fee (“Channel Subscription Services
”)."

So "streaming on Youtube/twitch.tv/..." is a subset of "streaming" in
general, i.e. you can be both (i) permitted to stream on twitch.tv (ii)
prohibited to stream on yt, without causing a conflict. However,
prohibiting streaming in general causes a conflict with e.g., a permission
to stream on yt.

> Is it the same “concept" as a geospatial constraint?
> Streaming in Australia versus Streaming (anywhere) ?

yes, but as noted already there are multiple ways of expressing similar
things. each with its own quirks.. e.g., what spatial leftoperands would
one use when specifying "a spatial constraint" on rule level?
https://www.w3.org/TR/odrl-vocab/#term-spatial? odrl:spatial is defined as "A
named and identified geospatial area with defined borders which is used for
exercising the action of the Rule"  so why not make it a refinement of the
action itself then? e.g. if I want to state that:

   - only Austrians are permitted (assignee/party refinement)
   - in Germany to purchase (action refinement OR rule constraint)
   - italian ice cream (asset refinement)
   - offered by Hungarian ice cream makers (assigner/party refinement)

Generally, I would probably opt for pulling as much "information" as
possible into the action itself which would not only allow for utilizing
things like odrl:implies and odrl:includedIn (e.g. ex:purchasingInGermany
odrl:includedIn odrl:purchase) but also aligns with what's outlined here
https://github.com/w3c/odrl/blob/master/formal-semantics/Compliance%20checking%20ODRL%20policies.md
.

> Perhaps our only way forward would be for ODRL Profiles to document why
they choose the approach they did….?

and/or describe the pros/cons of the different possibilities in the best
practice document.

- simon

On Sat, 9 Apr 2022 at 15:20, Renato Iannella <r@iannel.la> wrote:

> Hi Simon, I find the use of refinement with Asset/Party Collections more
> straightforward (than action refinement V rule constraint).
>
> The Collections are member-based and the refinement (which can be any type
> of narrowing query really) results in a subset of members.
>
> When i look at Example 14 here:
> https://www.w3.org/TR/odrl-model/#constraint-action
> I can clearly see that “printing at 1200dpi”  is narrower semantics than
> just “printing”.
>
> So, is “streaming on Youtube” narrower semantics than just “streaming”?
>
> Is it the same “concept" as a geospatial constraint?
> Streaming in Australia versus Streaming (anywhere) ?
>
> Both cases seems to imply that you are still streaming but in different
> physical or virtual worlds.
>
> Perhaps our only way forward would be for ODRL Profiles to document why
> they choose the approach they did….?
>
> Cheers - Renato
>