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Re: Semantic Tags (was several threads)

From: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
Date: Tue, 5 Feb 2013 14:58:50 +0000
Message-ID: <CAPRnXtk2tgX9u3QOJx7PKh1s43fF8CNgCshYqBBZWL5pW03GEg@mail.gmail.com>
To: Antoine Isaac <aisaac@few.vu.nl>
Cc: public-openannotation@w3.org
OK, let's leave it as suggested in future/ now then. :)

On Tue, Feb 5, 2013 at 2:56 PM, Antoine Isaac <aisaac@few.vu.nl> wrote:
> On 2/5/13 2:44 PM, Stian Soiland-Reyes wrote:
>> On Mon, Feb 4, 2013 at 6:04 PM, Robert Sanderson<azaroth42@gmail.com>
>> wrote:
>>>>> 3.  (Rob) Use oa:SemanticTag class, with foaf:page.  This is the same
>>>>> as 2. but with a looser predicate that isn't functional.
>>>> The last one is compact, does not interfere with other constructs, gives
>>>> a
>>>> little structure without too much commitment, is more declarative.
>>>> And I like how it reads for cases in which the URI is actually a page or
>>>> HTML document
>>>> ex:semtag a oa:SemanticTag ;
>>>>    foaf:page<http://omim.org/entry/104760>  .
>>> I think so too.
>> Is the idea that there is a semantic concept, here minted as
>> ex:semtag, which happens to have a foaf:page at
>> <http://omim.org/entry/104760>  ?  Or is a foaf:page considered
>> somewhat 'identifying' for an oa:SemanticTag? (Would it make sense to
>> have two distinct SemanticTag's with the same foaf:page?)
>>  From the text now at
>> http://www.openannotation.org/spec/future/core.html#Tagging (which
>> reads good, except figure Semantic Tag needs updating for class) is
>> that the foaf:page thing is a workaround for semantically tagging with
>> concepts which don't have a proper URI yet. Presumably you could still
>> use foaf:page for the 'normal' semantic tag as well without changing
>> much, ie.
>> :ann1
>>    oa:hasBody<http://dbpedia.org/resource/Paris>  .
>> <http://dbpedia.org/resource/Paris>  a oa:SemanticTag ;
>>      foaf:page<http://dbpedia.org/page/Paris>  ;
>> (and someone clever could relate this annotation with others which are
>> annotating the page)
>> I think the solution now in the HTML is workable. It is a bit
>> confusing because there are three different options, but thinking
>> about it now I think the foaf:page indirection is the most appropriate
>> for Paolo's use-case rather than hijacking the page URI and declare it
>> as some kind of semantic concept.
>> Perhaps the examples should be a bit clearer about where the actual
>> semantic tag URI can be found rather than using the generic<body1>
>> URIs:
>> <anno1>  a oa:Annotation ;
>>      oa:motivatedBy oa:tagging ;
>>      oa:hasBody<http://example.com/vocab/term1>  ;
>>      oa:hasTarget<target1>  ;
>>    <http://example.com/vocab/term1>  a oa:SemanticTag .
>>    <target1>  a dctypes:Image .
>> (As almost always the terms would come from a different namespace)
>>> For example, would clients be confused if they saw an Annotation that
>>> targeted a resource, say the dbpedia URI for Paris, and the RDF
>>> claimed that Paris was of class oa:SemanticTag ?  I think this
>>> actually *helps*, as the client would know not to dereference the URI
>>> looking for a document.  But perhaps we could have a better name for
>>> the class?
>> what we are talking about now sounds like a perfect fit for
>> skos:Concept - perhaps we should make oa:SemanticTag also subclass
>> skos:Concept (or use skos:Concept alone - but that might raise similar
>> in-from-the-outside concerns like my cnt:chars concerns, although here
>> it should be OK).
>> Forcing skos:Concept might have bigger impact than oa:SemanticTag
>> alone. I've checked with Sean in our office (one of the skos-reference
>> editors) who don't think so. (See below). Perhaps Antoine can fill in,
>> who wrote the skos-primer? :)
>> [12:17:35] Sean Bechhofer: The definition of skos:Concept is very open.
>> [12:17:39] Sean Bechhofer: [[SKOS leaves ample room for interpreting
>> the notion of concept, and many arti- facts from information science
>> and other fields fall in scope. As the SKOS Reference puts it [14], “a
>> SKOS concept can be viewed as an idea or notion; a unit of thought.
>> However, what constitutes a unit of thought is subjective, and this
>> definition is meant to be suggestive, rather than restrictive.”]]
>>  From http://www.w3.org/TR/skos-primer/
>>> SKOS has been designed to provide a low-cost migration path for porting
>>> existing organization systems to the Semantic Web. SKOS also provides a
>>> lightweight, intuitive conceptual modeling language for developing and
>>> sharing new KOSs. It can be used on its own, or in combination with
>>> more-formal languages such as the Web Ontology Language (OWL) [OWL]. SKOS
>>> can also be seen as a bridging technology, providing the missing link
>>> between the rigorous logical formalism of ontology languages such as OWL and
>>> the chaotic, informal and weakly-structured world of Web-based collaboration
>>> tools, as exemplified by social tagging applications.
>>> The aim of SKOS is not to replace original conceptual vocabularies in
>>> their initial context of use, but to allow them to be ported to a shared
>>> space, based on a simplified model, enabling wider re-use and better
>>> interoperability.
>> SKOS is quite permissive:
>> http://www.w3.org/TR/skos-reference/#concepts
>>> Other than the assertion that skos:Concept is an instance of owl:Class,
>>> this specification does not make any additional statement about the formal
>>> relationship between the class of SKOS concepts and the class of OWL
>>> classes. The decision not to make any such statement has been made to allow
>>> applications the freedom to explore different design patterns for working
>>> with SKOS in combination with OWL.
>> For instance it allows both these mixes:
>> <MyConcept1>  rdf:type skos:Concept , owl:Class .
>> <MyConcept2>  rdf:type skos:Concept , owl:ObjectProperty .
>> (This depends on OWL 2 punning, and would not be valid in OWL 1)
> Hi Stian,
> You're right, there's formally nothing that prevents skos:Concept to be used
> as type for other resources.
> But many people have expressed discomfort with this, as skos:Concepts are
> typically quite specific intellectual/informational artifacts, intuitively
> quite distinct from, say, persons.
> (note that Property foaf:focus has been - among others - minted to allow one
> to mint the 'concept of an entity from the real world' (e.g., a person) and
> relate it to the resource that stands for that entity of the real world,
> avoiding to conflate them in one resource)
> Declaring oa:SemanticTag a sub-class of skos:Concept ultimately depends on
> how much this group feels comfortable with what the SKOS group called
> 'crossing the streams'.
> Cheers,
> Antoine

Stian Soiland-Reyes, myGrid team
School of Computer Science
The University of Manchester
Received on Tuesday, 5 February 2013 14:59:39 UTC

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