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Re: Tag ontology

From: Danny Ayers <danny.ayers@gmail.com>
Date: Tue, 22 Mar 2005 18:07:32 +0100
Message-ID: <1f2ed5cd050322090770ede9cf@mail.gmail.com>
To: Richard Newman <r.newman@reading.ac.uk>
Cc: semantic-web@w3.org

On Tue, 22 Mar 2005 10:48:35 +0000, Richard Newman
<r.newman@reading.ac.uk> wrote:

>    Has anyone come across an ontology for tags (a la del.icio.us or
> Flickr)? I had a brief trawl of Schemaweb, but didn't find anything.
> Otherwise I'll write one :D

I can't remember where else, but I've seen
<dc:subject>tag</dc:subject> used for the purpose more than once. It's
what Morten's uses in his WordPress plugin (oh I like this so much!)
where tags used by an individual automatically become part of their
personal concept scheme, built using SKOS [1]. WordPress itself
organises the words as hierarchical categories, which Morten's
incorporated using skos:broader.

e.g. I might have tagged an item with "Programming", in my RSS feed
[2] that comes through as:

<item rdf:about="...">
<dc:subject>Programming</dc:subject>
<dc:subject rdf:resource="http://dannyayers.com/archives/author/site-admin/skos.rdf#c7"/>
...
</item>

The resource identifier refers to entries in a (autogenerated) schema [3], e.g. 

<Concept rdf:about="#c7">
	<dc:identifier>7</dc:identifier>
	<prefLabel>Programming</prefLabel>
	<rdfs:label>Programming</rdfs:label>
	<inScheme rdf:resource="#scheme"/>
	<broader rdf:resource="#c18"/>
</Concept>

The beauty of this is that it enables the easy-peasy tags for the
human while keeping things globally unambiguous for the machine. The
tag has a context. For convenience you might decide that parts of your
concept scheme are the same as that used by del.icio.us or Flickr, but
you can be as selective as you like, broadening and narrowing,
whatever. You can still just use the tag as itself, a little series of
chars, but there's more linguistic power available if you need it.

Cheers,
Danny.

[1] http://www.w3.org/2001/sw/Europe/reports/thes/1.0/guide/
[2] http://dannyayers.com/feed/rdf/
[3] http://dannyayers.com/archives/author/site-admin/skos.rdf

-- 

http://dannyayers.com
Received on Tuesday, 22 March 2005 17:07:33 UTC

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