W3C home > Mailing lists > Public > semantic-web@w3.org > March 2005

Re: tagging, scope, sweeping statements

From: Richard Newman <r.newman@reading.ac.uk>
Date: Sat, 26 Mar 2005 13:46:46 -0000
Cc: semantic-web@w3.org
To: Stan James <sjames@uni-osnabrueck.de>
Message-Id: <E1DFBck-0008Ke-00@vimb3>

Stan, 

On Mar 26, 2005, at 10:35, Stan James wrote:
-------------------
> Hi all,
> 
> Sorry if this has been beaten to death before (I checked the archives, 
> honest!) but I'm wondering how to express statements about a *class* of 
> URI's, as opposed to just one.  Seemed apropos to all this talk of 
> del.icio.us and tagging.

I don't think I've seen such a thing. It seems risky to do it by
examination, as it's a bit of a no-no to look "inside" a URI. The closest I
could think of would be to use RDFS classes to relate a bunch of
URIs/resources, and tag that, or to use a custom vocabulary.

> My project can, among other things, display the tags associated with a 
> page while you are browsing.  The problem with a del.icio.us-style 
> format is that I must infer generalizations: a tag of "news" on 
> http://www.cnn.com/ should also apply to a page deep within the site.  
> But a tag of "news" on http://news.google.com does NOT apply to every 
> page on google.com.

Though even a tag of "news" on cnn.com doesn't necessarily apply --- think
of a page where you manage your user preferences on the CNN site. Would you
tag that with "news"? Perhaps broadly, but it depends on the meaning of the
tag. You'd certainly tag with "CNN", but definitely not with "headlines".

> Rules of thumb can get me so far, but something explicit would be far 
> better.  I'm currently using something like this:
> 
> <item rdf:about="http://news.google.com/">
>   <title>Google News</title>
>   <link>http://www.google.com/</link>
>   <x:scope>*news.google.com/*</x:scope>
>   ...
> 
> Is there a standardized or more elegant way to express this?


I haven't seen one (bearing in mind my earlier point about looking inside
URIs). That seems a suitable workaround, except that this URI would also
match:

<http://example.com/bookmarks/news.google.com/exciting/>

It seems you need some vocabulary related to the URI RFCs...

HTH,
-R
Received on Saturday, 26 March 2005 13:47:37 GMT

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