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Re: More wording

From: Dimitris Kontokostas <kontokostas@informatik.uni-leipzig.de>
Date: Tue, 19 Apr 2016 23:23:31 +0300
Message-ID: <CA+u4+a0eVdvv=efNJu=AGs=zm5=BAhnxFxTVqGGAaoEeM9y3Yw@mail.gmail.com>
To: Karen Coyle <kcoyle@kcoyle.net>
Cc: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>, "public-data-shapes-wg@w3.org" <public-data-shapes-wg@w3.org>
Thank you Karen for offering editing suggestions.

On Tue, Apr 19, 2016 at 7:13 PM, Karen Coyle <kcoyle@kcoyle.net> wrote:

> Thanks, Peter. I see places in the spec where shapes are given agency in
> odd ways:
>
> "2.1.1 Node scopes (sh:scopeNode)
>
> Shapes define node scopes with the sh:scopeNode predicate"
>
> I would be more comfortable with:
>
> "The scope of a shape is defined with (?by?) the sh:scopeNode predicate."
>
> Also, I find places where it isn't clear whether a statement is about the
> shape graph or the data graph, such as:
>
> 2.1
> "Node scopes define a specific RDF node as scope."
>
> The RDF node in this case is a node in the data graph,* but that may not
> be clear to the reader.
>

I recently changed all examples and split the shapes & data graph to make
such cases more clear and in section 2 all selected focus nodes are marked
as green to further highlight how scopes & filters work.
in this case ex:Alice is referenced from the shapes graph and the node
should exist in the data graph as well


> Also, in some places I see "shape" and in others "Shape", and I believe
> these are referring to the same thing, so one form should be chosen.
>

This is a typo, "shape" should be used


> Again, I'd like to see editorial changes of this nature made, but am
> unclear how to coordinate with the current editors.
>

What Arnaud suggested is a good approach & faster but we can also transfer
your edits if you are not comfortable with pull requests.
let us know what you prefer

Best,
Dimitris


>
> kc
> * Yes, the data graph can be a SHACL document. That doesn't change this.
>
>
> On 4/18/16 1:19 PM, Peter F. Patel-Schneider wrote:
>
>> Yeah, I can see how that might be confusing.  You have to think that the
>> constraints of a shape are those that are (somehow) connected, or close,
>> to
>> the shape node, which is not what one might think of if one was making an
>> analogy to programming languages or even SPARQL.
>>
>> Your suggested wording looks promising to me.
>>
>> peter
>>
>>
>> On 04/18/2016 01:11 PM, Karen Coyle wrote:
>>
>>> OK, thanks, Peter. That truly wasn't clear, so I'll read further to see
>>> if
>>> this definition is followed in the text.
>>>
>>> But as an example, to me, the definition does not fit with the statement:
>>> "SHACL groups descriptive information and constraints that apply to a
>>> given
>>> data node into shapes. This document defines what it means for an RDF
>>> graph,
>>> referred to as the "data graph", to conform to a graph containing SHACL
>>> shapes, referred to as the "shapes graph"."
>>>
>>> I have trouble with "groups ... constraints ... into shapes" if a shape
>>> is an
>>> IRI/bnode. That is what made me think that shapes were intended to be
>>> graphs,
>>> not things (graphs being groups of 1 or more triples). (You wouldn't say:
>>> "groups names into Persons".) Perhaps:
>>>
>>> "A shape is an instance of the class sh:Shape, either an IRI or a blank
>>> node.
>>> The descriptive information and constraints that apply to a given data
>>> node
>>> are defined as the properties of a shape. A set of shapes that defines
>>> validation rules for a data graph (?or a portion of a data graph?) is
>>> called a
>>> 'shapes graph'. A shapes graph consists of one or more shapes."
>>>
>>> Closer?
>>>
>>> kc
>>>
>>> On 4/18/16 9:40 AM, Peter F. Patel-Schneider wrote:
>>>
>>>> There may be some misunderstanding here.  Shapes in SHACL are IRIs or
>>>> blank
>>>> nodes and come from RDF graphs that are to be considered as shapes
>>>> graphs.
>>>> RDF graphs are generally not considered to be instances of classes.
>>>>
>>>> SHACL documents should be clear that SHACL shapes are IRIs or blank
>>>> nodes
>>>> and not graphs or sets of triples.
>>>>
>>>>
>>>>
>>>> Here is some Turtle syntax for an RDF graph
>>>>
>>>> @prefix ex: <http://example.com/> .
>>>> @prefix ex: <http://www.w3.org/ns/shacl#> .
>>>>
>>>> ex:s1 a sh:Shape ;
>>>>     sh:scopeClass ex:Person ;
>>>>     ex:property [ a sh:PropertyConstraint ;
>>>>                ex:predicate ex:p1 ;
>>>>                   ex:valueShape ex:s2 ] ;
>>>>     ex:constraint [ a sh:PropertyConstraint ;
>>>>                     ex:predicate ex:p2 ;
>>>>            ex:valueShape [ a sh:Shape ;
>>>>                      ex:constraint [ a sh:NodeConstraint ;
>>>>                                            sh:class ex:Student ] ] ] .
>>>> ex:s2 a sh:Shape ;
>>>>     sh:constraint [ a sh:NodeConstraint ;
>>>>               sh:nodeKind sh:IRI ] .
>>>>
>>>> When treated as a shapes graph, an RDF graph that results from this
>>>> Turtle
>>>> syntax has three shapes in it
>>>> 1. http://example.com/s1
>>>> 2. http://example.com/s2
>>>> 3. the blank node that is allocated when matching
>>>>         [ a sh:Shape ;
>>>>        ex:constraint [ a sh:NodeConstraint ;
>>>>                  sh:class ex:Student ] ]
>>>>
>>>> peter
>>>>
>>>>
>>>> On 04/18/2016 09:03 AM, Karen Coyle wrote:
>>>>
>>>>> 2. Shapes
>>>>>
>>>>> Is: "Shapes are instances of the class sh:Shape and define a group of
>>>>> constraints that a set of focus nodes can be validated against."
>>>>>
>>>>> Suggest: "Shapes are graphs that are instances of the the class
>>>>> sh:Shape.
>>>>> Shapes define one or more focus nodes in a data graph and constraints
>>>>> on
>>>>> triples in those focus nodes. The triples in the focus nodes are
>>>>> validated
>>>>> against the constraints in the shape."
>>>>>
>>>>> I also suggest that we define "shape" as "an RDF graph of type
>>>>> sh:Shape" and
>>>>> not use "shape graph" but always use "shape" since "shape graph" is
>>>>> redundant.
>>>>>
>>>>> I can make this change if we have agreement on it. If I don't hear
>>>>> back I may
>>>>> make this definition an issue.
>>>>>
>>>>> kc
>>>>>
>>>>
>>>>
>>>
>>
> --
> Karen Coyle
> kcoyle@kcoyle.net http://kcoyle.net
> m: 1-510-435-8234
> skype: kcoylenet/+1-510-984-3600
>
>


-- 
Dimitris Kontokostas
Department of Computer Science, University of Leipzig & DBpedia Association
Projects: http://dbpedia.org, http://rdfunit.aksw.org, http://
http://aligned-project.eu
Homepage:http://aksw.org/DimitrisKontokostas
Research Group: AKSW/KILT http://aksw.org/Groups/KILT
Received on Tuesday, 19 April 2016 20:24:27 UTC

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