[RDF] Re: Authorization

[Graham Klyne]

At 05:36 PM 1/1/01 +0100, Jonas Liljegren wrote:
> > I think that this is all information that has to be coded in some way.
> > An RDF-based trust assessment framework should also describe its own
> > trust model, I think.  I don't think there are any universal answers
> > (though there probably will be some useful trust models that will be
> > commonly used).
>
>Yes.  I want to find one useful general model suitable for the type of
>system I am aiming at.  That is:
>
>The versioning system and the trust system are two aspects of the same
>thing.  To trust or not to trust is just one view. Other views is to
>see what is stated in diffrent times or from diffrent perspecives or
>scenarios.

Hmmm...   at one level I agree with this, but I was trying to suggest that 
no single model will fit all cases.  Rather, I see in RDF the potential to 
describe and integrate multiple models, without prejudice.  So, in a sense, 
RDF is your 'general model'?

[...]
>And I want this to be the same thing as the standard information
>queries. That is; a request for information includes a context for the
>request.  The answer to the request is given within the context.
>
>This is my definition for context withing Wraf.  The context is used
>as the base for a information request. It's sot of part of the
>request.  It contains your preferences used to select the wanted
>language, timeframe, version, inormation source, and more.
>
>The context is a hierarchy of contexts. It starts with the session,
>defining the time and place for the conversation.  Here we identifies
>the requestor agent and the service.  A specific request adds to the
>context.  There can be a series of questions and counter-questions,
>all within the context.

Sounds reasonable.  Your hierarchy of contexts is consistent with 
McCarthy/Guha's work, in that any statement is asserted within a 'nest' of 
contexts.  However, I think that this doesn't necessarily mean that 
contexts always form a strict hierarchy.

>The thing here is that the trust model and the other things is part of
>the preferences in the context. The preferences of the agent is
>overrided by the session preferences and later overrided by the
>explicit preferences for the specific request.

Ah, I see.  My view of contexts is much more general, but this is certainly 
a valid application.

>So what could we use for model as a testcase for this?  Something
>simple and useful for a typical community database.  Maby a use of
>ratings to sorting or filtering discussion entries, a little like
>slashdot, but simpler?

I feel that there is more groundwork to be done before I can seriously 
address some of these questions.  OTOH, if you have a well-specified 
use-case, maybe we can work together to try and model it?

#g

------------
Graham Klyne
(GK@ACM.ORG)