W3C home > Mailing lists > Public > www-rdf-interest@w3.org > April 2004

AW: AW: Distributed querying on the semantic web

From: Leo Sauermann <leo@gnowsis.com>
Date: Wed, 21 Apr 2004 10:42:06 +0200
To: "'Peter F. Patel-Schneider'" <pfps@research.bell-labs.com>
Cc: <www-rdf-interest@w3.org>
Message-ID: <002801c4277c$86df36e0$0b01a8c0@Bundeslade>

> > this implies that you are domain owner of www.whitehouse.gov if you 
> > make up this fictous resource.
> 
> Why?  What requirement is there on me that I cannot make up 
> URI resources from domains that I do not own?  What 
> expectation is there that only I make up URI resources from 
> domains that I do own?  This seems to go right back to the 
> days of pre-HTML/HTTP hypertext, where there was a 
> requirement that I had to only use valid hypertext links.

You may annotate existing uris and publish triples about them, no
problem. You do it all the time when using RDF schemas like DC or FOAF.
But when you make up something, use your own namespace. If you don't,
the owner of the namespace may get very angry (Namespace
grabbing/stealing) or may decide to use the uri for something completely
different and then your triples are bogus.

f.e. you must not use w3.org uris for your schemas if you are no w3
developer. This is not pre-html/http age, this is one of the three
pillars of the web: uri, http and html. The namespace use of domains is
common in XML namespaces. Thats how we ensure that no one fumbles in my
namespace definitions, the internic is my legal and business insurance
that no one steals my namespace.
The social practice of not domain stealing is here today and not 5 years
ago. I remember some discussions about domain stealing, people where not
happy about it, also in this list.


> 
> > F.E. I have stated on 
> http://www.gnowsis.com/wiki/GnowSis/LeoSThesis 
> > to use this 
> uri to identify the thesis, although not the pdf can be 
> > found there. This may be good social practice, to tell people what 
> > uris to use for identifying concepts. State on your homepage which 
> > resources are identified.
> 
> Again, why?   There may be perfectly good reasons to do otherwise.

Because if you want a global semantic web using consistent URIs you have
to tell people which URIs to use and use them yourself (dogfood) and
then hope that they spread so we all talk abou the same things. Isn't
this the idea of Semantic WEb and identifying things/concepts with URIs?


> > I would recommend that you are only allowed to make up URLs using 
> > domains you own!
> 
> I recommend otherwise.  There are many good reasons to use 
> URI references that are not know to have been used before and 
> that are not in domains that I own.  
> 
> For example, consider a situation where the WordNet 
> information has been put in the Semantic Web, say at 
http://realwordnet.org (wordnet.org having already been taken by a
religious broadcasting organization), and URI references like
http://realwordnet.org/#sailor are used in the RDF document that
contains the WordNet information.  I would like to say something about a
word that is not in WordNet (yet).  Why should I not be able to use a
URI reference like http://realwordnet.org/#Bushism?

This is a good example. I agree with you that it is possible to do so
and good practice. It allows you to do quick fixes for missing words.
Normally, institutions like wordnet or a wiki have a social process when
and how new words are entered. Perhaps you have to fill in some form,
answer an email, do the limbo, whatever. You may be trying to avoid
bureaucracy, which is ok. Perhaps this aspect is an advantage over
existing practice and can improve our way of communicating.
But a wiki/wordnet like URI space is an easy example. Their URIS are (by
agreement of the publishers and social practice in all wikis) always
identifiers for words or concepts.

On most homepages I have URLs like http://cm.bell-labs.com/cm/cs/
You won't be happy when I say
<http://cm.bell-labs.com/cm/cs/> <foafCorp:member>
<http://cm.bell-labs-com/cm/cs/PeterFPatelSchneider> 
and then publish this triple everywhere. Especially if all other people
do so, with slightly different URIs. They may mix up with other uris you
want to use. In a global semantic web, with the possiblitly that your
triples end up in my aggregator, I would hesitate to use other people's
domains.

W3C won't be happy when I invent a new RDF vocabulary, use their
namespace and change the meaning. Right now is a discussion in
RDF-Calendar where Dan Connoly wanted to use HIS OWN URI in a new way
and people where not pleased:

(iCal discussion on www-rdf-calendar)
At 5:04 PM -0500 04.4.14, Dan Connolly wrote:
>Summary: my discomfort with our timezone design motivated
>me to implement a new one. Who likes it? Who dislikes it?
Masahide Kanzaki replied:
>Please change namespace uri if you would introduce such a 
> significant change that makes most >existing RDFical files invalid.

so you aren't even allowed to change the meaning of your own URIs :-)))
don't try to change the meaning of other people's uris?!

As with social constructivism: everybody has his own view of the world,
if you express yours you can use public terms (=agreed uris owned by
other people) or if you are not happy with them invent your own terms
(=own uris from own domain). 

greetings
Leo Sauermann
Received on Wednesday, 21 April 2004 04:42:18 GMT

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