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Re: Definition of Shape

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Sat, 24 Jan 2015 14:31:15 -0800
Message-ID: <54C41D33.9010800@gmail.com>
To: Jose Emilio Labra Gayo <jelabra@gmail.com>
CC: Karen Coyle <kcoyle@kcoyle.net>, RDF Data Shapes Working Group <public-data-shapes-wg@w3.org>
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The glossary has an entry

Unscoped Constraint/Shape

which was supposed to be for Shape and Unscoped Constraint, i.e., asserting
that these two are the same.

Maybe it should have been

Shape/Unscoped Constraint

to make the scoping of Unscoped clearer.

peter


On 01/24/2015 12:14 PM, Jose Emilio Labra Gayo wrote:
> On Sat, Jan 24, 2015 at 5:48 PM, Peter F. Patel-Schneider 
> <pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>> wrote:
> 
> The glossary that I put together was at least partly an attempt to
> answer these sorts of questions.
> 
> 
>> Yes, and I really think it is very useful...that's why I dare to
>> contribute :)
> 
> In the glossary a shape (or unscoped constraint) is something that can
> only be evaluated against something, e.g., people with at least two
> friends would be a shape.
> 
> 
>> Do you propose that a Shape is the same as an "Unscoped constraint" ?
> 
>> If you think it is right so, should we put that definition in the
>> "Shape" slot? I am asking because I thought that a glossary on a Data
>> Shapes working group should have an entry on "Shapes"...
> 
>> What I was trying to stress with my proposal is that in the context of
>> this group a shape involves the triples surrounding an RDF node. I
>> think it is an important concept that can serve people who comes to the
>> group to understand what we are talking about...
> 
> 
> A scoped constraint includes both a shape and an indication of how it is
> to be applied, e.g., all people must be people with at least two friends
> would be a scoped constraint.  I would actually prefer to use just 
> "constraint" for scoped constraints but I was trying not to push this 
> particular preference for the meaning of constraint.
> 
> 
>> I think it makes sense to indicate the difference between "Scoped" and 
>> "Unscoped" constraints...maybe, in my proposal I was suggesting that a
>> Shape was composed of a set of constraints...which could also be called
>> "Compound constraints", but I would prefer not to complicate the
>> glossary...
> 
> 
> peter
> 
> 
> On 01/24/2015 08:08 AM, Karen Coyle wrote:
> 
> 
>> On 1/23/15 10:34 PM, Jose Emilio Labra Gayo wrote:
>>> On Fri, Jan 23, 2015 at 8:30 PM, Peter F. Patel-Schneider 
>>> <pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>
> <mailto:pfpschneider@gmail.com <mailto:pfpschneider@gmail.com>>> wrote:
>>> 
>> The glossary already contains a stab as this:
>>>> 
>>>> 
> https://www.w3.org/2014/data-shapes/wiki/Glossary#Unscoped_Constraint.2FShape
>
> 
>>>> 
> 
>>>> Yes, but I think we should have a simple definition of what a
>>>> Shape is and I think this definition could be it.
> 
>>> +1 for simple definition
> 
>>> I also think that in the
>>>> context of this group we can differentiate between a constraint
>>>> and a shape, saying that a shape is a set of constraints on some
>>>> RDF node.
> 
>>> Does the shape constrain? or does it define? In the Dublin Core work 
>>> the "shape" was called a "description" -- it describes the graph and 
>>> the desired rules for the graph. Whether one uses those rules to 
>>> constrain, or to inform, or to reject, or to simply shake one's head
>>> in dismay is a matter for the application that applies the rules.
>>> "Shape expressions" is very close to this meaning, and is looked on
>>> favorably within the DC community.
> 
>>> kc
> 
> 
> 
>>>> Apart from that, we can maintain the definitions of "constraint", 
>>>> "scoped constraint" and "unscoped constraint" which I also think 
>>>> they make sense.
> 
>>>> Best regards, Jose Labra
> 
>> peter
> 
> 
>> On 01/23/2015 10:10 AM, Jose Emilio Labra Gayo wrote:
>>> I edited the Glossary page to add a possible definition of shape as:
> 
>>> "A Shape is a set of constraints over the properties and objects
>> of an
>>> RDF node"
> 
>>> I think it is in accordance with the use of the term in the WG
>> and does
>>> not enter in conflict with other terms.
> 
>>> -- Saludos, Labra
>>> 
>>> 
>>> 
>>> 
>>> -- Saludos, Labra
> 
> 
> 
> 
> 
> -- Saludos, Labra
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Received on Saturday, 24 January 2015 22:31:47 UTC

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