- From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- Date: Fri, 09 Sep 2011 15:21:37 +0100
- To: public-prov-wg@w3.org
Hi Simon, On 09/09/2011 02:59 PM, Simon Miles wrote: > Hi Luc, > > >> I may not have been clear. I think that the requirement of roles to >> define derivation is a stronger justification than data structure >> uniformity. >> > OK. I think this raises three sub-issues: (i) that is not the > justification for mandatory roles currently given in the text; (ii) > Yes, text would need to be change > the use of roles in derivation assertions sounds like role types > rather than role names, i.e. there appears to be no necessity for the > no, in derivation, it's definitely role names you need, and unicity is required. > roles mentioned to be unique; (iii) roles are optional in derivation > assertions, so it seems odd that this be a rationale for them being > mandatory in other assertions. > optional to assert, but they do exist, as per inference. exactly like in use, roles are optional to assert > >> You still seem not to take into account the optional nature of asserting >> roles. Maybe, it's a question of presentation in the document. But >> ultimately, we are >> telling people you are free not to express roles. Under the bonnet, there >> will be an unspecified role. I don't understand what the problem is with >> this approach, where a default value is provided. >> > My problem with this approach is that I am unclear what "under the > bonnet" really means. I also agree with Graham's point that, whatever > it is, I don't know whether we should be standardising it. > > forget this sentence, sorry. I meant to say that not asserting a role is defined as asserting a role in the set "unspecified". > Regardless of any of the above, I still think the opaqueness of "Roles > are mandatory since they allow for uniform data structures" is the > most pressing issue. I think it answers a necessary question (why > mandatory?) but in an unhelpful way. > We would drop this statement, since derivation is a better justification. Luc > Thanks, > Simon > > > On 5 September 2011 10:20, Graham Klyne<GK@ninebynine.org> wrote: > >> On 05/09/2011 08:17, Luc Moreau wrote: >> >>> You still seem not to take into account the optional nature of asserting >>> roles. Maybe, it's a question of presentation in the document. But ultimately, >>> we are >>> telling people you are free not to express roles. Under the bonnet, there >>> will be an unspecified role. I don't understand what the problem is with >>> this approach, where a default value is provided. >>> >> I think there may be a mismatch here between designing a *system* and defining a >> *standard* - the point of a standard is to specify what is visibly exchanged >> between systems. >> >> In particular, if the role is optional, then it is unhelpful to say "Under the >> bonnet, there will be an unspecified role", because what exists "under the >> bonnet" is exactly an implementation choice. If I write a system that uses >> provenance information in a limited fashion that never involves roles (which is >> OK, as you have said they are optional), then there is no unspecified role under >> the bonnet. >> >> Thus, if the presence of a role is optional in the exchange of provenance >> information, then I think it should be optional in the model, as it is the >> exchangeable provenance information that we need to model here. Maybe, as you >> say, this is simply a matter of choosing appropriate phrasing. >> >> #g >> -- >> >> >> > > > -- Professor Luc Moreau Electronics and Computer Science tel: +44 23 8059 4487 University of Southampton fax: +44 23 8059 2865 Southampton SO17 1BJ email: l.moreau@ecs.soton.ac.uk United Kingdom http://www.ecs.soton.ac.uk/~lavm
Received on Friday, 9 September 2011 14:22:23 UTC