Re: [SKOS] How do I link external human-readable documents

Hello Tito


> I have been reading a lot about SKOS to organize
> things in categories, and almost got it [1]. I'm familiar with some of
> the concepts, but somewhat 'newbie' with RDF. Now, I'm a little lost
> about two very related things:
>
> 1. How do I Link external documents expanding the
> definition/representation  of a "Concept" (?)
>

I think the best way to do that is to use SKOS notes (or one of the
subproperties of notes, like skos:example, skos;description, etc.). A note
can link to an external resource. This is described in the SKOS Primer,
section 4.2 "Advanced Documentation Feature", subsection "Documentation as
a document reference" [1].

You can for example say something like :

<skos:Concept rdf:sbout="#music_concept">
  <skos:definition rdf:resource="http://en.wikipedia.org/wiki/Music" />
</skos:Concept>



>
> I would like to tell something like "This concept is also
> defined/represented on its own means by the following human-readable
> resources"; inventing something such:
>
> <skos:Concept rdf:about="#music_concept">
>         <skos:prefLabel>Music</skos:prefLabel>
>         <skos:definition>About Music..</skos:definition>
>         <!-- ... -->
>         <also_as>
>                 <link>http://en.wikipedia.org/wiki/Music</link>
>                 <link>https://music.domain.tld/</link>
>         </also_as>
>         <!-- ... -->
> </skos:Concept>
>
> ..... Some datasets(NYT) use "owl:sameAs", but this will introduce an
> inconsistency(as described in the specification) in the case that two
> linked concepts share same "owl:sameAs" with different prefLabel. I
> would like to avoid the inconsistency, but I have no clue what to do. I
> can imagine that I may link the same human-resource in two 'different'
> concepts.
>
> 2. In a very related problem.. How do I add data to a Concept?
> Coincidentally what I'm trying to organize are links. I imagine
> something like:
>
> <skos:Concept rdf:about="#music_concept">
>         <skos:prefLabel>Music</skos:prefLabel>
>         <skos:definition>About Music</skos:definition>
>         <items>
>                 <item>
>                         <title>News about music at.. </title>
>                         <description>Music News</description>
>                         <uri>http://news.music.tld/..</uri>
>                 </item>
>                 <item>
>                         <title>Title N</title>
>                         <description>Title N</description>
>                         <uri>http://uri.tld/</uri>
>                 </item>
>                 <!-- ... -->
>         </items>
>         <!-- ... -->
> </skos:Concept>
>
> In this example, items is the "data" contained in this defined Concept
> (I would like to distribute the ontology and data of this ontology in
> the same RDF).. I don't know if what I'm doing is correct. ! Can we tell
> with this representation that 'items' are the 'data' of this 'concept'?
> Or I'm telling non-sense?
>
> Any hint, much appreciated, Thanks for your time in advance (!)
>
>
Actually, the information is usually expressed the other way around : you
don't "add data to a Concept", you rather "categorize/annotate your
data/content/documents using Concepts".
To do this, you are free to use any property of your choice to link the
thing you categorize to a Concept. SKOS does not recommend one. One such
property is dcterms:subject [2]

So you say something like :

<rdf:Description rdf:about="http://theUriOfYourContent">
  <dcterms:subject rdf:resource="#music_concept" />
</rdf:Description>

I would encourage you to learn the much more readable RDf Turtle syntax [3]
to describe your data.

Hope this helps.
Thomas

[1] SKOS Primer advanced documentation features :
http://www.w3.org/TR/skos-primer/#secadvanceddocumentation
[2] DCTerms subject :
http://dublincore.org/documents/dcmi-terms/#terms-subject
[3] Turtle suntax : http://www.w3.org/TR/2014/REC-turtle-20140225/

-- 

*Thomas Francart* - Sparna
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