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Re: [dxwg] Indicate a conventional way to automatically validate data instances of application profiles (#698)

From: tombaker via GitHub <sysbot+gh@w3.org>
Date: Tue, 19 Mar 2019 15:08:26 +0000
To: public-dxwg-wg@w3.org
Message-ID: <issue_comment.created-474413466-1553008105-sysbot+gh@w3.org>
@rob-metalinkage writes:

> So this related Use Case is limited to finding what
> resources are available and canonical description of
> them

Okay, the requirement is resource discovery.

> its the responsibility of the chosen set of constraints
> languages and how they are used that determines if
> [traversing a graph to check conformance] is necessary.
> The Profiles Vocabulary is agnostic about this choice.

The Profiles Vocabulary implies a generalized notion of
"inheritance". Can SHACL, PDF, Schematron, CSV, etc, be
said to follow a common notion of inheritance?

> 1. the ability to declare conformance of a resource to a
>    specific profile

"Declaring conformance" goes well beyond resource
discovery.  The Profiles Vocabulary cannot be used to
_determine_ conformance of data to a specific profile;
that is the responsibility of the chosen constraint
language.  Is the goal simply to record a conformance
result in RDF data?  If so, are we to assume that
profiles and datasets are immutable?  (Because otherwise, 
the RDF data could be making an assertion that is no 
longer true.)

Users can use appropriate technologies to test for
themselves whether a resource conforms.  Is this not
better than trusting a "declaration of intent" (as you
put it) made in some RDF data at a particular point in
time?

Or is this not about conformance of data at all?

It is confusing to talk about conformance of "a resource" 
to a profile, when profiles are typically used to test 
the conformance of data, where you actually seem to mean
conformance of a particular expression of the profile 
(e.g., SHACL, Schematron) to The Profile in a more general 
sense".  

"Resource" is unhelpful as a choice of words because in
RDF, everything is a resource.

> 2. the ability to indicate that a specific profile
>    conforms to more general profiles 
>    
> (and I think we have just shown that this can't be done
> with any universally applicable constraint language - so
> thats the motivator here)

I'm seeing several types of conformance here:

1) Conformance of a profile to a standard used to express
   the profile (one example in PV shows something,
   presumably a SHACL graph, which conformsTo SHACL).

2) Conformance of data to a profile (which is perhaps out
   of scope of the PV?).

3) Conformance of a profile to another profile.  I am 
   struggling to see what this means in the general 
   sense.  Does a profile "conform" if it restricts 
   another?  If it "extends" another?  Or do you mean to 
   say that one profile actually validates another?
   Or do you mean that alternative expressions of a 
   profile conform to each other?

A requirement for discovering profiles related to
particular dataset would make sense to me, but not a
requirement for taking a SHACL/ShEx/Schematron/whatever
validation result at a given point of time and expressing
it as a "declaration of intent" in RDF.

> 3. a flexible way of referencing the various forms of
>    documentation in a way a machine can find an
>    appropriate resource for a particular function.

Right, resource discovery, though I'm unclear on what
"particular function" means here.

> It provides the new capability of declaration of intent
> w.r.t. to conformance in heirarchies however, and this
> thread has not affected that underlying requirement or
> the proposed solution, so I think it can be closed as
> out-of-scope.

I do not see a requirement to express "declaration of
intent w.r.t. to conformance in hierarchies" in RDF data
about profile documentation.  Where is the use case?  I
am struggling to see why this is considered to be in
scope.

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Received on Tuesday, 19 March 2019 15:08:27 UTC

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