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Re: shapes-ISSUE-197 (Defined ): "Defined" and "declared" used in multiple ways, and not defined [SHACL Spec]

From: Irene Polikoff <irene@topquadrant.com>
Date: Thu, 24 Nov 2016 21:14:55 -0500
To: <kcoyle@kcoyle.net>, <public-data-shapes-wg@w3.org>
Message-ID: <D45CFF32.C1D76%irene@topquadrant.com>
Several W3C specs use the words Œdefine¹, Œdescribe¹ and Œspecify¹ without
saying what these words mean. They also, at times, use them interchangeably.

For example, I think in the following passage from RDFS spec, Œdefine¹ and
Œdescribe¹ are used interchangeably:

> "rdfs:isDefinedBy is an instance of rdf:Property that is used to indicate a
> resource defining the subject resource. This property may be used to indicate
> an RDF vocabulary in which a resource is described.
> 
> A triple of the form:
> 
> S rdfs:isDefinedBy O
> 
> states that the resource O defines S.²
> 
The word Œdeclare¹ or its derivation such as Œdeclaration¹ is used more
rarely, but there is some usage. For example, in the RDFS spec:
> 
> "Although it is possible to combine use rdfs:domain and rdfs:range with
> sub-property hierarchies, direct support for such declarations are provided by
> richer Web Ontology languages such as OWL.²

OWL spec also makes an extensive use of words Œdefine¹ or Œdescribe¹ without
defining them. However, it attempts to define something called Œclass
description¹ and Œclass definition¹ e.g., in
https://www.w3.org/TR/2004/REC-owl-features-20040210/:

> "A class description is the term used in this document (and in the OWL
> Semantics and Abstract Syntax) for the basic building blocks of class axioms
> (informally called class definitions in the Overview and Guide documents). A
> class description describes an OWL class, either by a class name or by
> specifying the class extension of an unnamed anonymous class.²

And in https://www.w3.org/TR/owl-guide/

> Class Definitioninformal term for an owl:Class elementClass
> Descriptiondescribes an OWL class, either by a class name or by specifying a
> class extension of an unnamed anonymous class

The specification makes an extensive use of the phrase ³class description².

With this, I question the need to formally define words such as ³define²,
³describe², etc. because all other specs seem to rely on the common sense
interpretation of these words. It may be useful to define ³shape
description² and/or ³shape definition'. This could also help to resolve
Issue-209.

Irene Polikoff




On 11/24/16, 3:22 PM, "Karen Coyle" <kcoyle@kcoyle.net> wrote:

> I would advise choosing only one of them, and removing "sometimes" from
> the statement, which makes it something you cannot rely on - in other
> words, are they used other times for something else? is something else
> sometimes used in their place?:
> 
> "(In this document, the verbs <em>specify</em> or <em>declare</em> are
> sometimes used to express the fact that a node has property values in a
> graph.)"
> 
> I haven't read through the uses at this point.
> 
> kc
> 
> On 11/23/16 9:11 PM, Holger Knublauch wrote:
>>  I have gone through the whole document, replacing most usages of
>>  "define" with either "specify" or "declare". I have also added
>>  definitions of these two terms to the beginning of the document:
>> 
>>  
>> https://github.com/w3c/data-shapes/commit/92407af35824a7100845b4a84884c86de08
>> 6b9d7
>> 
>>  Holger
>> 
>> 
>>  On 19/11/2016 2:15, Irene Polikoff wrote:
>>>  I would use "specified" for the second meaning of "defined". I think
>>>  "declared" would work as well. "Described" - may be, but would not be
>>>  my first choice.
>>> 
>>>  On Thu, Nov 17, 2016 at 5:21 PM, RDF Data Shapes Working Group Issue
>>>  Tracker <sysbot+tracker@w3.org <mailto:sysbot+tracker@w3.org>> wrote:
>>> 
>>>      shapes-ISSUE-197 (Defined ): "Defined" and "declared" used in
>>>      multiple ways, and not defined [SHACL Spec]
>>> 
>>>      http://www.w3.org/2014/data-shapes/track/issues/197
>>>      <http://www.w3.org/2014/data-shapes/track/issues/197>
>>> 
>>>      Raised by: Karen Coyle
>>>      On product: SHACL Spec
>>> 
>>>>      >From Peter's email [1]:
>>> 
>>>      "Constraints are defined within a shape"
>>> 
>>>      "Defined within" is not defined.
>>> 
>>>      "Constraints that declare more than one parameters, such as
>>>      sh:pattern, are
>>>      not allowed to be declared more than once in the same constraint."
>>> 
>>>      The first two uses of "declare" come from section 6.2.  A core
>>>      definition is
>>>      needed.
>>> 
>>>      The last use of "declared" is not defined.
>>> 
>>>      "declare" is used for many different purposes, most of them undefined.
>>> 
>>>      ******* More analysis *******
>>>      The use of defined in its normal sense of "having a definition" is
>>>      ok. Example:
>>> 
>>>      "The parameter name is defined as the local name of the value of
>>>      sh:predicate."
>>> 
>>>      The use of defined to mean something like "takes as a value" or
>>>      "is coded as" is less clear:
>>> 
>>>      "Property constraints are defined in a shape with the property
>>>      sh:property."
>>>      "Based on the parameter IRIs on the tables, pre-bound variables
>>>      are defined using the parameter names."
>>> 
>>>      In some cases, the term "declare" is used in the same way as the
>>>      second meaning of define:
>>>      " Constraint components declare one or more parameter properties
>>>      and validation instructions (such as those implemented as SPARQL
>>>      queries) that can be used to perform the validation for the given
>>>      focus node and parameter values."
>>> 
>>>      Suggest:
>>>      - use "defined" for "is given a definition or meaning in this or
>>>      other texts
>>>      - do not use "declare"
>>>      - find a more precise term for the second meaning of "defined"
>>>      that specifically addresses the creation of properties and values,
>>>      regardless of how "definitional" they are.
>>> 
>>>      (Note how this is used in the SKOS document: "Therefore, while
>>>      SKOS can be used to describe a concept scheme, SKOS does not
>>>      provide any mechanism to completely define a concept scheme."
>>>      Could "describe" be used for this second meaning of "define"? That
>>>      still seems imprecise for the specific cases in SHACL.)
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>> 
> 
> -- 
> Karen Coyle
> kcoyle@kcoyle.net http://kcoyle.net
> m: 1-510-435-8234
> skype: kcoylenet/+1-510-984-3600
> 
> 
Received on Friday, 25 November 2016 02:15:35 UTC

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