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Re: profiles/modules/levels

From: Mark Skall <mark.skall@nist.gov>
Date: Tue, 29 Apr 2003 21:45:06 -0400
Message-Id: <5.1.0.14.2.20030429213736.00b235d8@mailserver.nist.gov>
To: Lofton Henderson <lofton@rockynet.com>
Cc: www-qa@w3.org

At 06:57 PM 4/29/2003 -0600, Lofton Henderson wrote:

>At 05:51 PM 4/29/03 -0400, Mark Skall wrote:
>
>>You're giving me a headache.  My responses are in-line.
>
>"I don't know why I even bother."  (Basil Fawlty)


Because you care . . .


>Cutting through copious amounts of misunderstanding, a couple of 
>corrections...
>
>>[...]
>>>Andrew's original comment was this:  "At the moment we have specific 
>>>checkpoints for p, m and l. But if someone wants to use a new type of 
>>>Dov called 'personality' or whatever then SpecGL is silent."
>>
>>And these checkpoints apply specifically to how a target spec implements 
>>SpecGL's requirements.  SpecGL is silent on "personality" because you 
>>can't give guidance on what you don't yet know (silence can be golden).
>
>Wrong!  Here is the whole point, and source of misunderstanding.
>
>SpecGL knows the definition of DoV, i.e., the abstract concept.  Target 
>spec authors know the definition of a DoV.  "...ways in which conformant 
>implementations may vary."  SpecGL has enumerated the 8 most common 
>DoV.  In fact, we can't think of any others, but Andrew worried that spec 
>authors might.  E.g., "levules" (I like that better than 
>'personality'.)  In 2004 (during the 18th Last Call of SpecGL?) Xblah WG 
>invents a new way to partition the standard Xblah 1.0 functions for 
>conformance. (Xblah 1.0 prohibits *functional* extensions, just to keep 
>life simple). None of P/M/L can be used in place of Levules -- none of 
>them fit the concept of Levules, without violating some fundamental of 
>their own definition.
>
>The Xblah WG determines (and QAWG agrees) that Levules fits the definition 
>of a DoV.  Of course SpecGL could never have anticipated Levules.  But 
>SpecGL could anticipate the invention some day of some new DoV.
>
>So SpecGL could say:  "If it's not one of the big 8, and it fits the 
>definition of a DoV, then your (target) specification MUST:  justify its 
>usage (just as you would for one of the big 8); and define its 
>relationship to the other (big-8) DoV".  (If it looks like a DoV, and 
>smells like a DoV, then treat it like a DoV.)


I guess here's the source of disagreement.  An additional DOV is an 
unanticipated (extra) way to partition specs.  There are an infinite number 
of other unanticipated things (extensions) that could be included in a 
target spec.  I guess I feel that to single out DOVs only is inconsistent. 
(Again, it also encourages adding additional DOVs).  If we value your point 
(you know I always do, he says smiling) then I think we should put this 
requirement in for all extensions (i.e., unanticipated extra concepts in 
the target spec).  Let's then put in a requirement to justify the usage of 
any new concept (extension).  This would appear in the extensions section and
would cover not only additional DOVs but everything else.

>Actually, I don't really care whether or not we do this in SpecGL.  But it 
>is perfectly well defined, how to do it.
>
>
>>>So, if "someone", i.e., a target specification, wanted to talk about its 
>>>own conformance to SpecGL, then yes, the new DoV could be described as 
>>>an extension to SpecGL.  However, SpecGL does not require that a target 
>>>specification say anything about its own conformance to 
>>>SpecGL.  Therefore the target specification in fact does not have to 
>>>talk about new-DoV as a dimension of variability, or describe its 
>>>relationship to other DoV, or any of the things that we *do* require 
>>>target specifications do for DoV.
>>
>>Correct.  But it can (through a conforming extension) talk about it 
>>specifically, rather than in general terms.  Also, I'm not sure why 
>>someone would add this new DOV.
>
>Neither am I.  But it could happen (which is what Andrew postulated.)
>
>>The point is to give guidance about when and why to use P, M and L's.  I 
>>think we should actually discourage other ways to do very similar things.
>
>I agree.
>
>
>>>Look at it another way.  If target specification uses 'profiles', then 
>>>SpecGL requires that the target specification talk about it.  If target 
>>>specification, in its conformance policy, defines a new way in which 
>>>conformant target implementations of target specification may vary 
>>>(i.e., a new dimension, "new-DoV"), then "SpecGL is silent".  Nothing in 
>>>SpecGL requires that target specification discuss it.
>>
>>Yes, but how can we require the target spec to discuss "it" when "it" is 
>>unknown.
>
>See above.  The containing concept of "it" -- the well-defined *concept* 
>of DoV -- is well known, even though we can't anticipate what "it" (a new 
>DoV instance) will be.
>
>-Lofton.
Received on Tuesday, 29 April 2003 21:45:55 GMT

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