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Re: bbc-programmes.dyndns.org

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Date: Sat, 21 Jun 2008 23:20:24 -0400
Message-Id: <12923F4D-9460-401E-A173-C31F91D7C561@gmail.com>
Cc: "Richard Cyganiak" <richard@cyganiak.de>, "Nicholas Humfrey" <Nicholas.Humfrey@bbc.co.uk>, public-lod@w3.org
To: "Peter Ansell" <ansell.peter@gmail.com>


On Jun 21, 2008, at 10:42 PM, Peter Ansell wrote:

> 2008/6/22 Alan Ruttenberg <alanruttenberg@gmail.com>:
>> The target of foaf:page is a thing, a web page.
>>
>> If you write a literal string, you are saying the foaf page is  
>> that string.
>> That's not what you want to say.
>
> Not if you type it with xsd:anyURI...

The you are saying the page is an xsd:anyURI, not a web page.

> Is there no separation allowed between the web and the semantic web  
> really?

Need there be?

> I thought the semantic web was based on logic not web structures?

Where did you get that idea?

> The semantic web doesn't gain anything from the result of that  
> page, which clearly has an
> alternative semantic representation available that you are already
> looking at when you see the foaf:page (or whatever predicate allows
> literals) statement.

It isn't about the result of what you fetch so much as it is speaking  
clearly, as I said earlier. The domain of foaf:page is a document.  
Neither a string nor an xsd:anyURI is a document. End of story.

> If you accept that the ontology you are using puts xsd:anyURI typed
> literals into a given field it is perfectly meaningful to use the
> string as you do any other URI string,

If you use another ontology than foaf, with a different relation  
whose domain is an xsd:anyURI, and that relation is documented in  
such a way as to make sense, then sure. I don't happen to see what is  
gained by doing that.

> just in a context which won't be interfered with, or interfere  
> itself with, the logic based semantic
> web rules.

I don't know what you mean by "interfered with" or what connection  
you are making between this particular choice and logic based semantic
web rules. It seems to me that the main benefit of using foaf:page  
here is that a lot of people know what it is supposed to mean.

>> The web page is
>>
>> <http://www.bbc.co.uk/programmes/b00b07kw.html> (the thing that  
>> the URI
>> denotes)
>
> It isn't an RDF Resource any more than my street and suburb address
> though, it is a simple human based locator which doesn't really have a
> need or want to be an RDF Resource IMO.

In both the case of the house, and the case of the web page, there is  
the resource - the house and the web page - and there is the address  
of the house and of the web page (also resources, but different  
ones). In discussion, one says different things about the address and  
the thing. For instance,

"http://www.bbc.co.uk/programmes/b00b07kw.html" has 45 characters.
or <http://www.bbc.co.uk/programmes/b00b07kw.html> uses the  
stylesheet <http://www.bbc.co.uk/programmes/r/23870/stylesheets/ 
decor.css>
or "http://www.bbc.co.uk/programmes/b00b07kw.html" is a name for  
<http://www.bbc.co.uk/programmes/b00b07kw.html>

"32 vassar avenue, cambridge, ma, usa" has 36 characters or
<the MIT Stata Center> foaf:depiction <http://en.wikipedia.org/wiki/ 
Image:Wfm_stata_center.jpg>
or "32 vassar avenue, cambridge, ma, usa"  entered into google maps,  
will locate <the MIT Stata Center>

> It is a coincidence IMO that it is defined in the same way that RDF  
> Resources are, and it isn't
> useful to mix everything up by presuming that URL's of web pages are
> useful as RDF Resources any more than arbitrary string literals.

First, in the RDF world, everything is an rdf:resource, including  
rdf:Literals. So they are "mixed up" already. While there were  
perhaps mistakes made in RDF, that web pages are considered resources  
is most certainly not one of them. Finally, I'll point out once again  
that the issue here isn't what is or is not a "good" resource. The  
issue is speaking clearly. If you want to talk about the literal, by  
all means do so, and if you want to talk about the web page,  
likewise. But don't confused one with the other.

-Alan

>
>> not
>>
>> "http://www.bbc.co.uk/programmes/b00b07kw.html"  (a string, or a  
>> URI, if you
>> wrote it using "http://www.bbc.co.uk/programmes/ 
>> b00b07kw.html"^^xsd:anyURI)
>>
>> It's not a matter of being for or against it. It's a matter of  
>> writing what
>> you mean.
>
> If you put xsd:anyURI there it is reasonably clear what you mean. Why
> are all URL's presumed to be RDF Resources by default? If you think
> all URI's and only URI's are RDF Resources then it might fit but I
> don't think that and hence won't "mean" it when I say it.
>
>> -Alan
>>
>> On Jun 21, 2008, at 10:11 PM, Peter Ansell wrote:
>>
>>>
>>> 2008/6/22 Richard Cyganiak <richard@cyganiak.de>:
>>>>
>>>> On 21 Jun 2008, at 23:41, Peter Ansell wrote:
>>>>>
>>>>> <foaf:page>http://www.bbc.co.uk/programmes/b00b07kw.html</ 
>>>>> foaf:page>
>>>>>
>>>>> Note that in the above notation the page is an actual URL  
>>>>> string and
>>>>> not an RDF resource which is intended because the person  
>>>>> already has
>>>>> the semantic resource and just wants to get to the human readable
>>>>> version.
>>>>
>>>> Uh.
>>>>
>>>> Peter, the domain of foaf:page is foaf:Document. You can't put an
>>>> rdfs:Literal there. This is a rather weird suggestion.
>>>>
>>>> Richard
>>>
>>> Sorry about that. Is there any ontology term which can do that?
>>>
>>> Why are people so anti putting http URL's in as Literals? If it  
>>> is an
>>> HTML page that relates to your current semantic "thing" then it  
>>> seems
>>> reasonable to have it as a literal to me.
>>>
>>> Peter
>>>
>>
>>
Received on Sunday, 22 June 2008 03:21:09 UTC

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