Re: Subjects & Tagging - Help?

On 3 Nov 2009, at 18:37, Nathan wrote:

> Alexandre Passant wrote:
>> Hi Nathan,
>> On 3 Nov 2009, at 18:16, Nathan wrote:
>>> Hi All,
>>>
>>> Hoping for a little bit of guidance here on tagging & assigning  
>>> subjects to content etc - I can't quite grasp how to describe what  
>>> an item of content is about; particularly in the context of a  
>>> normal blog post and with relation to tags/subjects/moat/commontag/ 
>>> scot etc.
>>>
>>> In short I've build a little mashup of a few services and some  
>>> linked data which extracts terms & subjects from an item of  
>>> content; and now I'm unclear of which ontologies to use.
>>>
>>>
>>> The info I can extract is "tag string" and mainly a dbpedia uri  
>>> for the tag (to give it real meaning I guess)
>>>
>>> example..
>>>    string:    Nuclear program of Iraq
>>>    URI:    http://dbpedia.org/resource/Nuclear_program_of_Iran
>>>
>>> also bearing in mind that I'll typically have 5-10 of these per  
>>> "post".
>>>
>>> On the face of it I'd assume I should be using the following for  
>>> each "tag" and leaving the string literal value out of the triples  
>>> altogether
>>>    http://purl.org/dc/terms/subject
>>>    http://www.holygoat.co.uk/owl/redwood/0.1/tags/taggedWithTag
>>>
>>> however, with MOAT/CommonTag/SCOT (and no doubt others) added in  
>>> to the equation I'm totally lost as which is the most fitting and  
>>> widely recognised for tagging content in this manner; is it worth  
>>> adding something to say that it was automatically tagged by a  
>>> machine? or including the string literal value of the tag(s)?
>> SCOT does not directly address the issue of 'tag meaning' but focus  
>> on modeling tagclouds and making them interoperable.
>> MOAT and CommonTag serve the same general purpose (defining what  
>> tag means, in terms of URIs) so you can use whatever you like -  
>> however, CommonTag is indexed by SearchMonkey so that is a clearer  
>> advantage for it and I'd then suggest to use that one if you  
>> develop an app on the Web.
>> A few differences between them however so far (it may evolve in the  
>> future, with ongoing work on CommonTag)
>> - CommonTag provides ways to make the difference between  
>> ctag:AuthorTag, ctag:ReaderTag and ctag:AutoTag while MOAT just  
>> make the difference between manual and auto-tag.
>> - MOAT models the "tagging action" (i.e. tri/quatri-partite model,  
>> based on - and extending - the Tag Ontology) and 'global  
>> meanings' (that can be used if you want to setup a tag server that  
>> deliver URIs / meanings for each tags, e.g. in a company.)
>> Hope that helps,
>
> cheers, it does.. but also leaves me thinking I need to be using:
> 	dc:subject
> 	tag:taggedWith
> 	ctag:means
> 	moat:tagMeaning
>
> surely this is an issue if they're all essentially the same?
>
> and leads me to a further question.. is there any way to express  
> that [dc:subject tag:taggedWith ctag:means moat:tagMeaning] are all  
> equal?

They are actually not the same.

The relationships ctag:means and moat:tagMeaning are used to define  
links between a tag and its meaning, not for linking the tagged  
resource to the meaning of the tag.
For that direct relationship , ctag:isAbout is the appropriate  
relationship (I'm just realizing it's not in the doc but in the  
ontology only [1]).
There is also moat:taggedWith that serve a similar purpose.

In addition, tag:taggedWith is there to link a resource to a tag, not  
to the URI that serves as a meaning for this tag.

Finally, regarding dc:subject, a tag can be used not as a subject  
(think of a webpage tagged "cool" or "todo", they are probably not  
used as subject) so the semantics of dc:subject is probably not what  
you want here.
However, this property can be enough if you know that the tags used  
are here as subject / topics.

Best,

Alex.

>
> thanks again,
>
> nathan
>

--
Dr. Alexandre Passant
Digital Enterprise Research Institute
National University of Ireland, Galway
:me owl:sameAs <http://apassant.net/alex> .

Received on Tuesday, 3 November 2009 18:50:11 UTC