- From: Irene Polikoff <irene@topquadrant.com>
- Date: Fri, 25 Nov 2016 12:05:12 -0500
- To: kcoyle@kcoyle.net
- Cc: Irene Polikoff <irene@topquadrant.com>, public-data-shapes-wg@w3.org
- Message-Id: <24B65097-6583-4C3D-9917-A2140025FC33@topquadrant.com>
How is this different from the following (interchangeable, as far as I can tell) use of the words of ‘define’, ‘describe’ , ‘declare’ and ‘represent’ in https://www.w3.org/TR/owl-ref/ <https://www.w3.org/TR/owl-ref/>?
A <>class description of the "enumeration" kind is defined with the owl:oneOf <http://www.w3.org/TR/2004/REC-owl-semantics-20040210/#owl_oneOf> property. The value of this built-in OWL property must be a list of individuals that are the instances <https://www.w3.org/TR/owl-ref/#Individual> of the class. This enables a class to be described by exhaustively enumerating its instances. The class extension of a class described with owl:oneOf contains exactly the enumerated individuals, no more, no less. The list of individuals is typically represented with the help of the RDF construct rdf:parseType="Collection", which provides a convenient shorthand for writing down a set of list elements. For example, the following RDF/XML syntax defines a class of all continents:
<owl:Class>
<owl:oneOf rdf:parseType="Collection">
<owl:Thing rdf:about="#Eurasia"/>
<owl:Thing rdf:about="#Africa"/>
<owl:Thing rdf:about="#NorthAmerica"/>
<owl:Thing rdf:about="#SouthAmerica"/>
<owl:Thing rdf:about="#Australia"/>
<owl:Thing rdf:about="#Antarctica"/>
</owl:oneOf>
</owl:Class>
and
The following example defines a class of individuals which have at least one parent who is a physician:
<owl:Restriction>
<owl:onProperty rdf:resource="#hasParent" />
<owl:someValuesFrom rdf:resource="#Physician" />
</owl:Restriction>
and
The following example describes the class of individuals who have the individual referred to as Clinton as their parent:
<owl:Restriction>
<owl:onProperty rdf:resource="#hasParent" />
<owl:hasValue rdf:resource="#Clinton" />
</owl:Restriction>
and
if the class description C1 is defined as a subclass of class description C2, then the set of individuals in the class extension of C1 should be a subset of the set of individuals in the class extension of C2. A class is by definition a subclass of itself (as the subset may be the complete set).
An example:
<owl:Class rdf:ID="Opera">
<rdfs:subClassOf rdf:resource="#MusicalWork" />
</owl:Class>
This class axiom declares a subclass relation between two OWL classes that are described through their names (Opera and MusicalWork).
I think we are wasting valuable time on this particular item. [A I said previously, I do think that the terms ‘shape description’ or ‘shape definition’ are worth defining]
Further, to me, the version of the sentence below that uses “defined using” is much clearer and more intuitive than the version that uses “of”.
Irene
> On Nov 25, 2016, at 11:34 AM, Karen Coyle <kcoyle@kcoyle.net> wrote:
>
> That's fine if the usage is unambiguous and follows the normal meaning of "define", and there are many clear uses of define in document, which I noted previously. If it is used to mean "provides a definition for" then it's fine. There are other times when it is used to mean "has as value" or simple "is" - as in
>
> "Note also that a qualified cardinality constraint defined using sh:qualifiedValueShape, sh:qualifiedMinCount, and sh:qualifiedMaxCount is equivalent to a sh:partition constraint that..."
>
> In those cases, the term "defined" is less precise than:
>
> Note also that a qualified cardinality constraint of either sh:qualifiedValueShape, sh:qualifiedMinCount, and sh:qualifiedMaxCount is equivalent to a sh:partition constraint that..."
>
> There's no need for define here, and nothing is really being defined. The use of these properties is not definitional, it simply "is" and should be stated that way.
>
> kc
>
> On 11/24/16 6:14 PM, Irene Polikoff wrote:
>> Several W3C specs use the words ‘define’, ‘describe’ and ‘specify’
>> without saying what these words mean. They also, at times, use them
>> interchangeably.
>>
>> For example, I think in the following passage from RDFS spec, ‘define’
>> and ‘describe’ 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*.”
>>
>> The word ‘declare’ or its derivation such as ‘declaration’ 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.”
>>
>>
>> OWL spec also makes an extensive use of words ‘define’ or ‘describe’
>> without defining them. However, it attempts to define something called
>> ‘class description’ and ‘class definition’ 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.”
>>
>>
>> And in https://www.w3.org/TR/owl-guide/
>>
>> Class Definition
>> informal term for an owl:Class element
>> Class Description
>> describes 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 “class description”.
>>
>> With this, I question the need to formally define words such as
>> “define”, “describe”, etc. because all other specs seem to rely on the
>> common sense interpretation of these words. It may be useful to define
>> “shape description” and/or “shape definition'. This could also help to
>> resolve Issue-209.
>>
>> Irene Polikoff
>>
>>
>>
>>
>> On 11/24/16, 3:22 PM, "Karen Coyle" <kcoyle@kcoyle.net
>> <mailto:kcoyle@kcoyle.net <mailto: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/92407af35824a7100845b4a84884c86de086b9d7
>>
>> 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>
>> <mailto:sysbot+tracker@w3.org <mailto: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 <mailto:kcoyle@kcoyle.net> <mailto:kcoyle@kcoyle.net <mailto:kcoyle@kcoyle.net>> http://kcoyle.net <http://kcoyle.net/>
>> m: 1-510-435-8234
>> skype: kcoylenet/+1-510-984-3600
>>
>>
>
> --
> Karen Coyle
> kcoyle@kcoyle.net <mailto:kcoyle@kcoyle.net> http://kcoyle.net <http://kcoyle.net/>
> m: 1-510-435-8234
> skype: kcoylenet/+1-510-984-3600
Received on Friday, 25 November 2016 17:05:49 UTC