On Dec 12, 2008, at 9:47 AM, Oleg Gryb wrote:
> Yoichi,
>
> In your reasoning I don't really see a fundamental difference
> between "sign an agreement" and "show a reason of denial"
> obligations. In the latter case and in my example the "next step"
> for the user may be signing up a fee-based agreement for the bill
> payment service.
The position I have taken on the TC is that we should differentiate
between Obligations (Decision + ACTION) and Causality (Decision +
INFORMATION). The primary reason for this is that Obligations are
becoming overloaded to the point that they are a general mechanism for
anything not covered in the spec. There is currently a proposal to
push Obligations to the Rule level (to solve some causality Use Cases)
which I think will only exacerbate the problem.
My proposal therefore, is that we do not extend Obligations to the
Rule level and we introduce a mechanism that is specifically intended
for cause/advice responses. This doesn't solve my concern with
Obligations but it does provide what I feel is a more precise
mechanism for dealing with this aspect of the decision response.
The counter argument to my approach is that users will not be able to
easily differentiate between what it "actionable" and what is
"informational" so no additional benefit will be had from adding an
explicit causal response mechanism (that is very similar to how
Obligations work). For the specific case you have below I would answer
that "sign" is a verb which makes this an ACTION. Therefore it would
be an Obligation. "Show reason of denial" does not require action by
the PEP so it would be an Advice (Cause, whatever we decide to call
it :). As an Obligation the Policy Writer should be able to expect
that the action will transpire and if not some sort of error condition
will occur. The latter will not be bound to an explicit action and
subsequent processing may or may not act independently from the
original decision request/response.
I would be very interested in hearing what the user community thinks
of this.
thanks
b
