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Re: Resource ambiguity [was Re: Can "http://danbri.org" and "http://danbri.org/" URIs represent different things?]

From: Xiaoshu Wang <wangxiao@musc.edu>
Date: Mon, 06 Jul 2009 10:35:03 -0400
Message-ID: <4A520B97.80602@musc.edu>
To: David Booth <david@dbooth.org>
CC: Pat Hayes <phayes@ihmc.us>, Alan Ruttenberg <alanruttenberg@gmail.com>, Dan Brickley <danbri@danbri.org>, "www-tag@w3.org WG" <www-tag@w3.org>
David Booth wrote:
> On Thu, 2009-07-02 at 15:50 -0500, Pat Hayes wrote:
>   
>> On Jul 2, 2009, at 3:42 PM, Alan Ruttenberg wrote:
>>
>>     
>>> On Tue, Jun 30, 2009 at 8:54 PM, Dan Brickley<danbri@danbri.org>  
>>> wrote:
>>>       
>>>> Hello TAG,
>>>>
>>>> Talking with some SW folk about OpenID, and whether my "me-the- 
>>>> person" URI
>>>> could be practically usable as my OpenID, I came up with this  
>>>> corner-case:
>>>>
>>>> Could http://danbri.org be a URI for "me the person", and http://danbri.org/
>>>> be a document about me (and also serve as my OpenID)?
>>>>
>>>> As I understand HTTP, any client must request something, so the  
>>>> former isn't
>>>> directly de-referencable. The client has to decide to ask for / from
>>>> danbri.org instead. But they're still different URIs, aren't they?
>>>>
>>>> Is...
>>>>
>>>> <Person  xmlns:foaf="http://xmlns.com/foaf/0.1"/
>>>>         rdf:about="http://danbri.org">
>>>>  <openid>
>>>>    <Document rdf:about="http://danbri.org/"/>
>>>>  </openid>
>>>> </Person>
>>>>
>>>> ...at all feasible? I guess it depends on how exactly we think  
>>>> about the
>>>> "add a / to the end" step...
>>>>         
>>>       
>>>> From an RDF point of view the URI strings are different means that
>>>>         
>>> they can denote different things.
>>>
>>> I guess the question I have about this is: Why be so "clever"?
>>>       
>> I think I can answer that. Because people are. In fact, people use the  
>> same name for a person and the person's website and the person's name,  
>> etc., often without even noticing that they are doing it, and  
>> certainly without falling into instant incoherence or having their  
>> brains catch fire. But our inference engines can't handle this kind of  
>> ambiguity, at present. So it would be handy if a notational convention  
>> could be adopted that allowed the dumb machinery to keep its prissy  
>> distinctions distinct, while allowing human readers to be sloppy  
>> without even noticing that they are being sloppy. This idea is an  
>> elegant step in that direction, if it can be made to work.
>>     
>
> I agree that a *clear* notational convention would be helpful.   But I
> do *not* think that using subtly different URIs to distinguish between
> Dan and his web page is a wise design choice.   It is just inviting
> confusion and error.  The likely result is that *both* URIs would be
> used for both purposes, without the intended distinction.  I think it
> would be better to "ambiguously" use the same URI for both than to use
> two URIs that differ so subtly that even the HTTP protocol cannot
> distinguish them.
>   
What is "subtle" and "clear"? "x" differs from "x/" by one character. So 
does "x" to "xy"?

With regard to Dan's proposal: the issue should be about if it will 
damage the current practice of using "/" or existing protocol.  If not, 
then by all means use the convention.  On the other hand, also by all 
means to make people be aware of your intension what the "subtle" 
syntactic different "clearly" means.

Xiaoshu
Received on Monday, 6 July 2009 14:35:49 GMT

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