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Re: summarizing proposed changes to charter

From: Eric Prud'hommeaux <eric@w3.org>
Date: Wed, 13 Aug 2014 08:58:01 -0400
Message-ID: <CANfjZH21v2iJ37EePZxRKt8yN4QBs9tq7na0BhuTz1VtmRUUZA@mail.gmail.com>
To: Peter Patel-Schneider <pfpschneider@gmail.com>
Cc: David Booth <david@dbooth.org>, Arnaud <lehors@us.ibm.com>, public-rdf-shapes@w3.org
On Aug 13, 2014 7:12 AM, "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
wrote:
>
> I'm still not getting this at all.
>
> How does canonicalization help me determine that I got the RDF data that
I expected (exact or otherwise)?  For example, how does canonicalization
help me determine that I got some RDF data that tells me the phone numbers
of my friends?
>
> I just can't come up with a use case at all related to RDF data
validation where canonicalization is relevant, except for signing RDF
graphs, and that can just as easily be done at the surface syntax level,
and signing is quite tangential to the WG's purpose, I think.

I think another use case is being able to diff or compare graphs with text
tools. For instance, David Robillard requested that turtle tests be
expressed in a canonical format. Of course this pushes the comparison
problem from graph isomorphism to canonicalization, which is arguably
harder.

Imposing an ordered traversal of a schema and corresponding data would at
least give you a predictable graph, which, combined with some bnode
re-labeling, may suffice for these use cases (including signature). I
purpose that the charter not include normalization or canonicalization but
that supporters provide use cases to see which technologies (help) meet
them. If none do, that indicates that we need to assemble the relevant
parties in a different WG.

> peter
>
>
>
> On 08/12/2014 09:17 PM, David Booth wrote:
>>
>> I think "canonicalization" would be a clearer term, as in:
>>
>>    "OPTIONAL - A Recommendation for canonical serialization
>>     of RDF graphs and RDF datasets."
>>
>> The purpose of this (to me) is to be able to validate that I got the
*exact*
>> RDF data that I expected -- not merely the right classes and predicates
and
>> such.  Would you be okay with including this in the charter?
>>
>> Thanks,
>> David
>>
>> On 08/12/2014 10:00 PM, Peter F. Patel-Schneider wrote:
>>>
>>> I'm still not exactly sure just what normalization means in this context
>>> or what relationship it has to RDF validation.
>>>
>>> peter
>>>
>>>
>>> On 08/12/2014 06:55 PM, David Booth wrote:
>>>>
>>>> +1 for all except one item.
>>>>
>>>> I'd like to make one last ditch attempt to include graph normalization
>>>> as an
>>>> OPTIONAL deliverable.  I expect the WG to treat it as low priority,
>>>> and would
>>>> only anticipate a normalization document being produced if someone
>>>> takes the
>>>> personal initiative to draft it.  I do not see any significant harm in
>>>> including it in the charter on that basis, but I do see a benefit,
>>>> because if
>>>> the WG did somehow get to it then it would damn nice to have, so that
>>>> we could
>>>> finally validate RDF data by having a standard way to compare two RDF
>>>> documents for equality, like we can routinely do with every other data
>>>> representation.
>>>>
>>>> Peter, would that be okay with you, to include graph normalization as
>>>> OPTIONAL
>>>> that way?
>>>>
>>>> Thanks,
>>>> David
>>>>
>>>> On 08/12/2014 08:55 PM, Eric Prud'hommeaux wrote:
>>>>>
>>>>> Hi all, we can have a face-to-face at the W3C Technical Plenary in
>>>>> November if we can quickly endorse a good-enough charter.  As it
>>>>> stands now, it isn't clear that the group will be able to reach
>>>>> consensus within the Working Group, let alone get through the member
>>>>> review without objection.
>>>>>
>>>>> Please review the proposals that I've culled from the list.  I
>>>>> encournage compromise on all our parts and we'll have to suppress the
>>>>> desire to wordsmith. (Given the 3-month evaluation period,
>>>>> wordsmithing won't change much anyways.)
>>>>>
>>>>>
>>>>> separate semantics:
>>>>>
>>>>>    "Peter F. Patel-Schneider" <pfpschneider@gmail.com> - Message-ID:
>>>>> <53E2AFBD.9050102@gmail.com>
>>>>>      A syntax and semantics for shapes specifying how to construct
shape
>>>>> expressions and how shape expressions are evaluated against RDF
graphs.
>>>>>    "Dam, Jesse van" <jesse.vandam@wur.nl> - Message-ID:
>>>>> <63CF398D7F09744BA51193F17F5252AB1FD60B24@SCOMP0936.wurnet.nl>
>>>>>      defining the the (direct) semantics meaning of shapes and
>>>>> defining the
>>>>> associated validation process.
>>>>>
>>>>>    opposition: Holger Knublauch
>>>>>
>>>>>    proposed resolution: include, noting that if SPARQL is judged to be
>>>>> useful for the semantics, there's nothing preventing us from using it.
>>>>>
>>>>>
>>>>> make graph normalization optional or use-case specific:
>>>>>
>>>>>    "Peter F. Patel-Schneider" <pfpschneider@gmail.com> - Message-ID:
>>>>> <53E2AFBD.9050102@gmail.com>
>>>>>      3 OPTIONAL A specification of how shape verification interacts
with
>>>>> inference.
>>>>>    Jeremy J Carroll <jjc@syapse.com> - Message-Id:
>>>>> <D954B744-05CD-4E5C-8FC2-C08A9A99BA9F@syapse.com>
>>>>>      the WG will consider whether it is necessary, practical or
>>>>> desireable
>>>>> to normalize a graph...
>>>>>      A graph normalization method, suitable for  the use cases
>>>>> determined by
>>>>> the group....
>>>>>    David Booth <david@dbooth.org> - Message-ID:
>>>>> <53E28D07.9000804@dbooth.org>
>>>>>      OPTIONAL - A Recommendation for normalization/canonicalization
>>>>> of RDF
>>>>> graphs and RDF datasets that are serialized in N-Triples and N-Quads.
>>>>> opposition - don't do it at all:
>>>>>    "Peter F. Patel-Schneider" <pfpschneider@gmail.com> - Message-ID:
>>>>> <53E3A4CB.4040200@gmail.com>
>>>>>      the WG should not be working on this.
>>>>>
>>>>>    proposed resolution: withdrawn, to go to new light-weight, focused
>>>>> WG,
>>>>> removing this text:
>>>>>    [[
>>>>>    The WG MAY produce a Recommendation for graph normalization.
>>>>>    ]]
>>>>>
>>>>>
>>>>> mandatory human-facing language:
>>>>>
>>>>>    "Dam, Jesse van" <jesse.vandam@wur.nl> - Message-ID:
>>>>> <63CF398D7F09744BA51193F17F5252AB1FD60B24@SCOMP0936.wurnet.nl>
>>>>>      ShExC mandatory, but potentially as a Note.
>>>>>    David Booth <david@dbooth.org> - Message-ID:
>>>>> <53E28D07.9000804@dbooth.org>
>>>>>      In Section 4 (Deliverables), change "OPTIONAL - Compact,
>>>>> human-readable
>>>>> syntax" to "Compact, human-readable syntax", i.e., make it required.
>>>>>    Jeremy J Carroll <jjc@syapse.com> - Message-Id:
>>>>> <54AA894F-F4B4-4877-8806-EB85FB5A42E5@syapse.com>
>>>>>
>>>>>    opposition - make it OPTIONAL
>>>>>    "Peter F. Patel-Schneider" <pfpschneider@gmail.com> - Message-ID:
>>>>> <53E2AFBD.9050102@gmail.com>
>>>>>      OPTIONAL A compact, human-readable syntax for expressing shapes.
>>>>>
>>>>>    proposed resolution: keep as OPTIONAL, not mentioning ShExC, but
>>>>> clarifying that it's different from the RDF syntax.
>>>>>
>>>>>
>>>>> report formats:
>>>>>    Dimitris Kontokostas <kontokostas@informatik.uni-leipzig.de>
>>>>>      provide flexible validation execution plans that range from:
>>>>>        Success / fail
>>>>>        Success / fail per constraint
>>>>>        Fails with error counts
>>>>>        Individual resources that fail per constraint
>>>>>        And enriched failed resources with annotations
>>>>>
>>>>>    proposed resolution: no change, noting that no one seconded this
>>>>> proposal.
>>>>>
>>>>>
>>>>> test suite/validator:
>>>>>
>>>>>    Dimitris Kontokostas <kontokostas@informatik.uni-leipzig.de>
>>>>>      Validation results are very important for the progress of this
>>>>> WG and
>>>>> should be a standalone deliverable.
>>>>>    David Booth <david@dbooth.org> - Message-ID:
>>>>> <53E28D07.9000804@dbooth.org>
>>>>>      Test Suite, to help ensure interoperability and correct
>>>>> implementation.
>>>>> The group will chose the location of this deliverable, such as a git
>>>>> repository.
>>>>>
>>>>>    proposed resolution: leave from charter as WGs usually choose to
>>>>> do this
>>>>> anyways and it has no impact on IP commitments.
>>>>>
>>>>
>>>
>>>
>>>
>>>
Received on Wednesday, 13 August 2014 12:58:33 UTC

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