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Re: Usage of degrees of conformance

From: Lofton Henderson <lofton@rockynet.com>
Date: Fri, 09 Aug 2002 10:36:20 -0600
Message-Id: <>
To: Dominique HazaŽl-Massieux <dom@w3.org>
Cc: reagle@w3.org, www-qa@w3.org


I like your suggestion.  More details below, including some responses to 
Joseph's comments...

At 02:26 PM 8/9/02 +0200, Dominique HazaŽl-Massieux wrote:
>-----Message suivi-----
> > From: Joseph Reagle <reagle@w3.org>
> > I
> > don't think [degrees of conformance] should be encouraged regardless
> > though it seems to be
> > popular at the W3C now.)
> > [...]
> >
> > It's based on experience. [...]  I pursued, for a short
> > time, "levels of conformance." The reason we went down this path was
> > because of an inability to focus on what was going to be implemented, make
> > the hard decisions, and cut down on the complexity.

I agree that, all too often, this is the reason for discretion, 
optionality, implementation-dependent behaviors, etc.  We have, in the 
editors draft of Spec Guidelines (SpecGL), a guideline (GL) aimed at 
discretionary and optional features:

[0] http://www.w3.org/QA/WG/2002/08/qaframe-spec-0804.html#Gd-define-discretion

It is still in development, and the QAWG has yet to resolve some issues 
about possible additional checkpoints, advisory warnings about using some 
variants of discretion, etc.

>[...]Since then, I consider every optional feature in a spec I author a
> > personal "demerit" <smile/>,

Maybe we should add this as a way to score GL8's checkpoints -- 
"discretionary demerits"!

>[...] Regardless, I also remember talking to Ian while
> > he was trying to come to terms with the concepts of the levels in WAI 
> and I
> > appreciated that when a specification is as prescriptive as descriptive 
> (if
> > not more so) levels *may* be a useful tool and I think the framework 
> arrived
> > at is very good *if* the situation merits it.

Yes, there is a place for it.  The trick is to discourage people from using 
it (conformance levels, optional features, etc) as an expedient to avoid 
hard decisions.  We have started to do that at GL8 ([0] above), but haven't 
yet applied it to "conformance levels" (Dom's [2] below).

Turning to Dom's comments...

>The latest editor draft of the spec GL [2] doesn't make any
>recommendation in this regard. Maybe it should?

I think so.  I'm starting to see that checkpoint 11.1 ([2]) has a 
relationship to GL5 "Specify conformance policy."  Conformance policy is 
one of the dimensions of variability (DoV), and therefore carries a warning 
that excessive variability is evil, variability creates complexity, 
simplicity is good, etc.  It almost seems that the gist of 11.1 belongs in 
GL5, where the policy is defined.  It could then get a pointer from GL11 
(which is about documentation features and mechanics).

(Oops, I notice that there is still a flagged issue in GL5, about how to 
word the variability warning for this GL and its CKs.)

>Specifically, the checkpoint doesn't differentiate between a profiled
>specification vs a specification using degrees of conformance (ala WAI
>or QA). Rather, it does differentiate them, but not enough (in my
>opinion): a profile is a specification per se and the conformance clause
>belongs to each profile, whereas in the WAI/QA case, one specification
>holds the 3 degrees of conformance.
>I would suggest that degrees of conformance be strongly discouraged for
>anything but guidelines, or maybe more broadly, anything but "foundation
>or abstract" specifications [3].

Per the last QAWG telecon, I have to redraft 11.1 ([2]), and I'll try to 
integrate your comments.  You could also send me proposed draft rewording, 
if you like.  The next SpecGL editors draft (for next Wed telecon) will be 
posted Monday night (8/12).


>2. http://www.w3.org/QA/WG/2002/08/qaframe-spec-0804.html#Ck-define-all-levels
>3. http://www.w3.org/QA/WG/2002/08/qaframe-spec-0804.html#document-categories
>Dominique HazaŽl-Massieux - http://www.w3.org/People/Dom/
Received on Friday, 9 August 2002 13:07:57 UTC

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