Re: Profile Best Practice document with alternative text about Policy and subclasses of Rule

Thanks for the in-depth analysis Michael….

I think the point raised by David also was that the ODRL Model is based on semantic web technologies, which implies the ‘open-world assumption’.
Hence, we cannot stop additional assertions being created.

That is, when we wrote:
   "A Policy MUST have at least one permission, prohibition, or obligation property values of type Rule”
We said nothing about what else a Policy could have.

So an ODRL Profile can create a new subclass of Rule, say “Safety" and related property “safety”, then a valid Policy would be one that has at least one of the "golden three” properties and the new “safety” property.

So, I think we are in a better place than we thought last month.
I think the current Spec is ok, and all we need to do in the Profile Best Practices is show a good use case for a new type of Rule.

Cheers - Renato

> On 11 Jun 2020, at 00:58, Michael Steidl (NIT) <mwsteidl@newsit.biz> wrote:
> 
> Hi all,
> at the call on 8 June this raised erratum was discussed: https://github.com/w3c/poe/issues/303 <https://github.com/w3c/poe/issues/303>
> Simply summary: the ODRL data model and vocabulary define that only a single specific subclass of Rule can be used as type for the Policy properties permission, prohibition  and obligation.
> Open issue: how to use subclass of Rule defined by a Profile in a Policy? By the current Recommendation this is not easy:
>  
> At the call we discussed two options:
> The data model and the vocabulary stay untouched, the only solution is creating a new property in a new subclass of Policy and to define the new Rule subclass as type of this new property.
> Pro: no change of the Recommendation is required
> Con: a kind of pointless rule dummy must be used with permission or prohibition or obligation if the goal of the news Profile is to use only new subclasses of Rule.
> Currently the vocabulary defines for the Policy property permission [1]: its type (Range) is Permission [2], and Permission defines In Range of: permission.
> (Corresponding definitions are applied to the properties prohibition [3] and obligation [4]).
> This is changed to permission/prohibition/obligation have  as type (Range) Rule [5] – this opens the window of opportunity for applying any subclass of Rule as type.
> Open issue: what about this “In Range Of” in the vocabulary, this is not reflected explicitly by the formal OWL documents of the vocabulary, may be generated from the range setting of properties. “In Range of” appears to be not a relationship defined for RDF or OWL.
>  
> General note: at the call David reminded us of sticking to the base design of ODRL, and this includes only permission, prohibitions and obligations should be expressed as Rule, not anything away from it. We may consider how to guarantee that. This is my suggestion: https://github.com/w3c/odrl/issues/10 <https://github.com/w3c/odrl/issues/10>
>  
> Based on this discussion I modified – as agreed at the call – the Profile Best Practice document https://w3c.github.io/odrl/profile-bp <https://w3c.github.io/odrl/profile-bp>
> ALTERNATIVE TEXT is shown in the section Additional Rule Subclasses https://w3c.github.io/odrl/profile-bp/#rule <https://w3c.github.io/odrl/profile-bp/#rule>
> ALTERNATIVE TEXT is shown in the section Additional Policy Subclasses https://w3c.github.io/odrl/profile-bp/#policy <https://w3c.github.io/odrl/profile-bp/#policy>
> ALTERNATIVE TEXT is shown in the section What may be ignored, and what not https://w3c.github.io/odrl/profile-bp/#oos1 <https://w3c.github.io/odrl/profile-bp/#oos1>
> “ALTERNATIVE TEXT no change applied …” reflects option a) above
> “ALTERNATIVE TEXT constraint of types …” reflects option b) above
>  
> What’s next:
> Please review if the created ALTERNATIVE TEXTs reflect options a) and b) in their context properly – prior to the next call on 6 July.
> … and post any comments to this email list.
> At the next call we should agree if we keep both alternatives in the Best Practice or if we select one of them as “the solution”.
>  
> Best,
> Michael
>  
>  
> [1] https://www.w3.org/TR/odrl-vocab/#term-permission <https://www.w3.org/TR/odrl-vocab/#term-permission>
> [2] https://www.w3.org/TR/odrl-vocab/#term-Permission <https://www.w3.org/TR/odrl-vocab/#term-Permission>
> [3] https://www.w3.org/TR/odrl-vocab/#term-prohibition <https://www.w3.org/TR/odrl-vocab/#term-prohibition>
> [4] https://www.w3.org/TR/odrl-vocab/#term-obligation <https://www.w3.org/TR/odrl-vocab/#term-obligation>
> [5] https://www.w3.org/TR/odrl-vocab/#term-Rule <https://www.w3.org/TR/odrl-vocab/#term-Rule>
>  
> =============================================================
> Gesendet von / sent by:
> Michael W. Steidl
> www.linkedin.com/in/michaelwsteidl <http://www.linkedin.com/in/michaelwsteidl>
> Email: mwsteidl@newsit.biz <http://www.newsit.biz/>
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