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Encoding tags in DRS

From: Phil Archer <parcher@icra.org>
Date: Fri, 29 Feb 2008 15:51:39 +0000
Message-ID: <47C82A0B.20809@icra.org>
To: Public POWDER <public-powderwg@w3.org>

One of our use cases [1] calls for DRs to support free text tags and
for it to be possible to associate such tags with a a semantic
definition. For example, I might want to associate my tag 'red' with
something more prescriptive like 'ff0000'. The use case (which comes
from my.opera) talks about the Dahut and cryptozoology.

I've been thinking about how we might do this in POWDER ('cos the
present text has all the problems we're just overcoming with our
two-part system).

OK, how's this:

<POWDER xmlns="http://www.w3.org/2007/05/powder#"
         xmlns:ex="http://example.org/vocab#">

   <attribution>
     <maker>http://authority.example.org/foaf.rdf#me</maker>
     <issued>2007-12-14</issued>
   </attribution>

   <DR>
     <URISet>
       <includeHosts>example.org</includeHosts>
     </URISet>

     <Descriptors>
       <ex:color>red</ex:color>
       <ex:shape>square</ex:shape>
       <displayText>Everything on example.org is red and
square</displayText>
       <displayIcon>http://example.org/icon.png</displayIcon>
     </Descriptors>

     <Tags mapsTo="http://ui.example.com#panicButton">red square</Tags>

   </DR>

</POWDER>

Here our DR contains the URISet and _two_descriptive units. My proposal
is that a DR must contain at least one of these. The Descriptor set is
the familiar one, but there's now a Tags element that contains a white
space separated list of tags. The mapsTo attribute (optional) might then
link to the Descriptors block in another POWDER doc or any other bit of
RDF that had a semantically-defined definition. So the semantics here
are "when I say red and square I mean the same as ui.example.com mean by
their term 'panicButton'.

I guess we could make the tags an element within the Descriptors but
this doesn't feel right. A tag is a free-form thing, Descriptions are
much more tightly constrained and I fear we might imply that
ex:color='red' and ex:shape='square' both meant the same as panicButton
- they don't.

I did toy with saying that a DR can only have Tags or Descriptors but
this is pointless since you can create 2 DRs with the same URISet in the
same POWDER doc to archive what's written above.

Incidentally, I believe I'm right in saying that tagging systems in
general do not allow white space within tags, i.e. Eiffel Tower is 2
tags. If this is wrong and we should support tags with white space we
can do that too but we'd end up with

<TagSet mapsTo="http://ui.example.com#panicButton">
   <tag>red</tag>
   <tag>square</tag>
</TagSet>

Any comments?


Phil.

[1]

-- 
Phil Archer
Chief Technical Officer,
Family Online Safety Institute
w. http://www.fosi.org/people/philarcher/
Received on Friday, 29 February 2008 15:51:49 GMT

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