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Subject: My Conclusion re An RDF/S/OWL-DL representation
The overlap of requirements addressed by RDF/S/OWL and the requirements
of a TAG markup are very interesting and make RDF/S/OWL attractive for
marking up a Test Assertion. However I think there are a few very significant
mismatches (as far as I understand it):
* OWL and to some extent RDF/S have been designed for an 'Open System' where
any set of assertions can be mixed with any other
* there is no weighting of one assertion over another, each have equal weight
* the set of assertions stated with RDF/S/OWL cannot be closed to further
assertions or given precedence over other assertions
* one assertion in OWL cannot replace a previous one, only supplement it
I feel these and a few other features of RDF/S/OWL make it on the whole
a poor match for some of the important aspects of test assertions and so
I wouldn't particularly favor its use for TAs. Mostly this is due to the
need to designate a set of assertions as being in some way complete and
authoritative and part of a particular group. Of course this is a matter
of degree in that further assertions might well be added, but not as
freely, I feel, as OWL would allow.
Further developments in the Semantic Web do seem to be addressing such
less-open system requirements but it remains to be seen whether this will
lead to something useful enough for test assertions, I think.
--
Stephen D. Green
Partner
SystML, http://www.systml.co.uk
Tel: +44 (0) 117 9541606
http://www.biblegateway.com/passage/?search=matthew+22:37 .. and voice
Quoting stephen.green@systml.co.uk:
> A roundtrip works quite well, to get an idea of how others
> might use RDF/RDFS/OWL to represent the same Test Assertion
> model/example. An export from the semantic wiki Halo project
> (which imports well back into the wiki) looks like this for
> the exact same example:
>
> <?xml version="1.0" encoding="UTF-8"?>
> <!DOCTYPE rdf:RDF[
> <!ENTITY rdf 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
> <!ENTITY rdfs 'http://www.w3.org/2000/01/rdf-schema#'>
> <!ENTITY owl 'http://www.w3.org/2002/07/owl#'>
> <!ENTITY smw 'http://smw.ontoware.org/2005/smw#'>
> <!ENTITY smwdt 'http://smw.ontoware.org/2005/smw-datatype#'>
> <!ENTITY wiki 'http://localhost/mediawiki/index.php/Special:URIResolver/'>
> <!ENTITY wikiurl 'http://localhost/mediawiki/index.php/'>
> <!ENTITY property
> 'http://localhost/mediawiki/index.php/Special:URIResolver/Property-3A/'>
> ]>
>
> <rdf:RDF
> xmlns:rdf="&rdf;"
> xmlns:rdfs="&rdfs;"
> xmlns:owl ="&owl;"
> xmlns:smw="&smw;"
> xmlns:wiki="&wiki;"
> xmlns:wikiurl="&wikiurl;"
> xmlns:property="&property;">
> <!-- Ontology header -->
> <owl:Ontology rdf:about="">
> <smw:exportDate
> rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime";>2008-01-28T10:00:16+00:00</smw:exportDate>
> </owl:Ontology>
> <!-- exported page data -->
> <smw:Thing rdf:about="&wiki;Widget_precondition1">
> <rdfs:label>Widget precondition1</rdfs:label>
>
> <smw:hasArticle rdf:resource="&wikiurl;Widget_precondition1"/>
> <rdfs:isDefinedBy
> rdf:resource="&wikiurl;Special:ExportRDF/Widget_precondition1"/>
> <rdf:type rdf:resource="&wiki;Category-3AWidget"/>
> <property:Property rdf:resource="&wiki;WidgetSize_Medium"/>
> </smw:Thing>
> <smw:Thing rdf:about="&wiki;Widget_ta001">
> <rdfs:label>Widget ta001</rdfs:label>
> <smw:hasArticle rdf:resource="&wikiurl;Widget_ta001"/>
>
> <rdfs:isDefinedBy rdf:resource="&wikiurl;Special:ExportRDF/Widget_ta001"/>
> <rdf:type rdf:resource="&wiki;Category-3AWidget"/>
> <property:Prose
> rdf:datatype="http://www.w3.org/2001/XMLSchema#string";>has a red button
> on top</property:Prose>
> <property:SpecRef
> rdf:datatype="http://www.w3.org/2001/XMLSchema#string";>101:1a</property:SpecRef>
> <property:Precondition rdf:resource="&wiki;Widget_precondition1"/>
> </smw:Thing>
> <!-- auxilliary definitions -->
> <owl:ObjectProperty rdf:about="&property;Precondition">
>
> <rdfs:label>Precondition</rdfs:label>
> <smw:hasArticle rdf:resource="&wikiurl;Property:Precondition"/>
> <rdfs:isDefinedBy
> rdf:resource="&wikiurl;Special:ExportRDF/Property:Precondition"/>
> </owl:ObjectProperty>
> <owl:DatatypeProperty rdf:about="&property;SpecRef">
> <rdfs:label>SpecRef</rdfs:label>
> <smw:hasArticle rdf:resource="&wikiurl;Property:SpecRef"/>
> <rdfs:isDefinedBy
> rdf:resource="&wikiurl;Special:ExportRDF/Property:SpecRef"/>
>
> </owl:DatatypeProperty>
> <owl:DatatypeProperty rdf:about="&property;Prose">
> <rdfs:label>Prose</rdfs:label>
> <smw:hasArticle rdf:resource="&wikiurl;Property:Prose"/>
> <rdfs:isDefinedBy
> rdf:resource="&wikiurl;Special:ExportRDF/Property:Prose"/>
> </owl:DatatypeProperty>
> <smw:Thing rdf:about="&wiki;WidgetSize_Medium">
> <rdfs:label>WidgetSize Medium</rdfs:label>
>
> <smw:hasArticle rdf:resource="&wikiurl;WidgetSize_Medium"/>
> <rdfs:isDefinedBy
> rdf:resource="&wikiurl;Special:ExportRDF/WidgetSize_Medium"/>
> </smw:Thing>
> <owl:ObjectProperty rdf:about="&property;Property">
> <rdfs:label>Property</rdfs:label>
> <smw:hasArticle rdf:resource="&wikiurl;Property:Property"/>
> <rdfs:isDefinedBy
> rdf:resource="&wikiurl;Special:ExportRDF/Property:Property"/>
> </owl:ObjectProperty>
>
> <owl:Class rdf:about="&wiki;Category-3AWidget">
> <rdfs:label>Widget</rdfs:label>
> <smw:hasArticle rdf:resource="&wikiurl;Category:Widget"/>
> <rdfs:isDefinedBy
> rdf:resource="&wikiurl;Special:ExportRDF/Category:Widget"/>
> </owl:Class>
> <!-- reference to the Semantic MediaWiki schema -->
> <owl:AnnotationProperty rdf:about="&smw;hasArticle">
> <rdfs:isDefinedBy rdf:resource="http://smw.ontoware.org/2005/smw"/>
>
> </owl:AnnotationProperty>
> <owl:AnnotationProperty rdf:about="&smw;exportDate">
> <rdfs:isDefinedBy rdf:resource="http://smw.ontoware.org/2005/smw"/>
> </owl:AnnotationProperty>
> <owl:Class rdf:about="&smw;Thing">
> <rdfs:isDefinedBy rdf:resource="http://smw.ontoware.org/2005/smw"/>
> </owl:Class>
> <!-- Created with Semantic MediaWiki, http://ontoworld.org/wiki/SMW -->
> </rdf:RDF>
>
> --
> Stephen D. Green
>
> Partner
> SystML, http://www.systml.co.uk
> Tel: +44 (0) 117 9541606
>
> http://www.biblegateway.com/passage/?search=matthew+22:37 .. and voice
>
>
>
> Quoting stephen.green@systml.co.uk:
>
>> Attached is a screen dump of how this representation looks in
>> the semantic wiki. It revealed a few modeling issues...
>>
>> [Incidentally there was a missing spec ref - it should look like this:
>>
>> <Widget rdf:ID="Widget_precondition1">
>> <property>
>> <WidgetSize rdf:ID="WidgetSize_Medium"/>
>> </property>
>> </Widget>
>> <Widget rdf:ID="Widget_ta001">
>> <specRef
>> rdf:datatype="http://www.w3.org/2001/XMLSchema#string";>101:1a</specRef>
>> <prose rdf:datatype="http://www.w3.org/2001/XMLSchema#string";>has a
>> red button on top</prose>
>> <precondition rdf:resource="#Widget_precondition1"/>
>> </Widget>
>> ]
>>
>> There is an issue to note, I think, with the use of a 'precondition'
>> - it is a bit of a modeling problem in that the precondition actually
>> functions as a restricted subclass of the test assertion or its predicate.
>>
>> * If the precondition is itself a predicate it needs everything
>> a test assertion needs except the spec ref. I.e. maybe it needs
>> its own ID so one precondition can be used in multiple predicates.
>>
>> * This then leads to some issues:
>>
>> * Why not then just use an assertion?
>>
>> * What then is the difference between precondition and prerequisite?
>>
>> * Doesn't this logic mean that a test assertion actually amounts
>> an extension of a superclass which is an assertion (extended by
>> adding spec ref)?
>> * Then a prerequisite could be the equivalent of a precondition
>> in that both reference both assertions and test assertions (or
>> instantiate, rather than reference the assertion and test
>> assertion classes).
>>
>> * So having a new superclass of test assertion called 'assertion'
>> could answer three problems:
>> 1. no need for both prerequisites and preconditions
>> 2. distinction between
>> a. test assertions and
>> b. assertions/predicates which aren't test assertions as such
>> 3. a different target can be associated with the assertion/predicate
>> of the precondition/prerequisite - a different target to the TA's
>>
>> Another issue arose while trying to implement the model:
>>
>> Does a TA have a target or does a target have a TA?
>>
>> The latter proves to be most useful in my example (to allow grouping
>> of TAs under the category of a shared target or target class).
>>
>> Best regards
>> - Steve
>>
>>> I tried the OWL-DL representation with WikiMedia's SemanticWiki
>>> / Halo Project OWL extensions and found that it needed tightening
>>> up a lot more (eliminating the redundant elements).
>>>
>>> This resulted in the representation below which seems quite satisfactory
>>> as a mere demo of how a TA might be represented for the semantic web:
>>>
>>> <?xml version="1.0"?>
>>> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#";
>>> xmlns:owl="http://www.w3.org/2002/07/owl#"; xmlns="http://localhost#";
>>> xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#";
>>> xml:base="http://localhost";>
>>> <owl:Ontology rdf:about=""/>
>>> <owl:Class rdf:ID="Property"/>
>>> <owl:Class rdf:ID="WidgetSize">
>>> <rdfs:subClassOf>
>>> <owl:Class rdf:ID="Size"/>
>>> </rdfs:subClassOf>
>>> </owl:Class>
>>> <owl:Class rdf:ID="Target"/>
>>> <owl:Class rdf:about="#Size">
>>> <rdfs:subClassOf rdf:resource="#Property"/>
>>> </owl:Class>
>>> <owl:Class rdf:ID="Widget">
>>> <rdfs:subClassOf rdf:resource="#Target"/>
>>> </owl:Class>
>>> <owl:ObjectProperty rdf:ID="precondition">
>>> <rdfs:domain rdf:resource="#Target"/>
>>> </owl:ObjectProperty>
>>> <owl:DatatypeProperty rdf:ID="prerequisite">
>>> <rdfs:domain rdf:resource="#Target"/>
>>> <rdfs:range rdf:resource="http://www.w3.org/2001/XMLSchema#string"/>
>>> </owl:DatatypeProperty>
>>> <owl:DatatypeProperty rdf:ID="specRef">
>>> <rdfs:domain rdf:resource="#Target"/>
>>> <rdfs:range rdf:resource="http://www.w3.org/2001/XMLSchema#string"/>
>>> </owl:DatatypeProperty>
>>> <owl:FunctionalProperty rdf:ID="property">
>>> <rdfs:domain rdf:resource="#Target"/>
>>> <rdfs:range rdf:resource="#Property"/>
>>> <rdf:type rdf:resource="http://www.w3.org/2002/07/owl#ObjectProperty"/>
>>> </owl:FunctionalProperty>
>>> <owl:FunctionalProperty rdf:ID="value">
>>> <rdfs:domain rdf:resource="#Property"/>
>>> <rdfs:range rdf:resource="http://www.w3.org/2001/XMLSchema#string"/>
>>> <rdf:type rdf:resource="http://www.w3.org/2002/07/owl#DatatypeProperty"/>
>>> </owl:FunctionalProperty>
>>> <owl:FunctionalProperty rdf:ID="prose">
>>> <rdfs:range rdf:resource="http://www.w3.org/2001/XMLSchema#string"/>
>>> <rdfs:domain rdf:resource="#Target"/>
>>> <rdf:type rdf:resource="http://www.w3.org/2002/07/owl#DatatypeProperty"/>
>>> </owl:FunctionalProperty>
>>> <Widget rdf:ID="Widget_precondition1">
>>> <property>
>>> <WidgetSize rdf:ID="WidgetSize_Medium"/>
>>> </property>
>>> </Widget>
>>> <owl:AllDifferent/>
>>> <Widget rdf:ID="Widget_ta001">
>>> <specRef rdf:datatype="http://www.w3.org/2001/XMLSchema#string"/>
>>> <prose rdf:datatype="http://www.w3.org/2001/XMLSchema#string";>has a
>>> red button on top</prose>
>>> <precondition rdf:resource="#Widget_precondition1"/>
>>> </Widget>
>>> </rdf:RDF>
>>> <!-- Created with Protege (with OWL Plugin 3.3.1, Build 430)
>>> http://protege.stanford.edu -->
>>>
>>>
>>> --
>>> Stephen D. Green
>>>
>>> Partner
>>> SystML, http://www.systml.co.uk
>>> Tel: +44 (0) 117 9541606
>>>
>>> http://www.biblegateway.com/passage/?search=matthew+22:37 .. and voice
>>>
>>>
>>>
>>> Quoting stephen.green@systml.co.uk:
>>>
>>>> Second attempt after first seems to have got stuck (in filters?)
>>>> This time with attachment as zip
>>>>
>>>> Contains two OWL files, one with a TA ontology - classes and properties,
>>>> the other with an example individual TA in OWL-DL using the ontology.
>>>>
>>>> --
>>>> Stephen D. Green
>>>>
>>>> Partner
>>>> SystML, http://www.systml.co.uk
>>>> Tel: +44 (0) 117 9541606
>>>>
>>>> http://www.biblegateway.com/passage/?search=matthew+22:37 .. and voice
>>>
>>>
>
>
>
>
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