Re: Uniform access to metadata: XRD use case.

Williams, Stuart (HP Labs, Bristol) wrote:
> Hello Xiaoshu,
>
> <snip/>
>   
>> What makes me reverse my course? As I can now understand, the reason is 
>> that when we are speaking at the higher level, there are only a few 
>> words/concepts that we can use.  For the Web, there are only three 
>> things that are clearly defined.  URI, awww:Representation, 
>> Resource.  
>> According to the SIR model that I have used to define all information 
>> system,
>>
>> URI is the *Symbol*
>> awww:Representation the *Information*,
>> Resource the *Referent*.
>>
>> Resource, is thus, what exists in the Web.  Existence, according to 
>> Quine's definition, is the value of a bounded variable.  It is things 
>> that has meaning or significance.
>>
>> Representation is Information, which, as defined by Dretske, is 
>> objective.  And Information must have structure, which, w.r.t. to the 
>> Web, it is the format of awww:Representation.
>>     
>
> I really don't think you are very far way from where I, the TAG and probably most of the web community are - though we (you and I at least) seem make a lot 'noise' about the apparent disagreement.
>
> What seems missing here is a discussion of how the "information" stands in relation to the "referent". AUI in webarchitecture the intention is that the 'information' conveys the current state of the 'referent'. With that constraint... if you provide 'information' that enables me to present an 'image' or a 'narrative' on a screen - it is that 'image' or that 'narrative' that is the referent as opposed to whatever thing or combination of things that are the subject matter of the depicted in the image or discussed in the narrative.
>   
I have thought about this issue too. I understand your concern.  For 
instance,, if the light-information emitted from an object makes me to 
believe that the object is red.  Then, I would prefer that the object in 
question is the source of information, i.e., either by emitting or the 
light bounced off it.

The most fundamental answer (i.e., I am speaking without another other 
terminologies) is that if you want to make sure of the Referent in 
question is the source of information, you need more evidence. This is 
what we do in science and in social life (such as to dispute rumors).

In terms of the Web, this comes down to the dual nature of the HTTP-URI. 
If you treat the HTTP-URI as a URN, I don't think you will have that 
concern anymore.  Your concern is mostly because the HTTP-URI is also 
URL.  Hence, when we are talking about resource denoted by an HTTP-URI, 
we don't know when we are using it in which sense.  So, additional 
evidence needed to tell the one sense from the other.

This is why I have proposed the scheme-less URI as the only URN for the 
Web.   (Thanks for pointing me out its potential conflict with relative 
URI.  Nevertheless, if TAG really takes this proposal, that can be 
easily solved).

Hence, if "//example.com/XiaoshuWang" is used to denote me.  The 
information returned by "http://example.com/XiaoshuWang" would not 
indicate that its source is from "//example.com/XiaoshuWang".  The 
"http:" only suggests that it is providing information about 
"//example.com/XiaoshuWang".  Similarly, if there were another protocol 
called *call*, which by some regulation and technology, to connect to my 
phone, then you can do "call://example.com/Xiaoshu", i.e., to call me in 
real person. If you trust the *call* protocol, then you can remove your 
doubt.  Otherwise, you will also need more evidence to reinforce your 
belief as with the "http" case.

Xiaoshu

>> Thus, when we talk about the Web, these are all the terminologies that 
>> we have at our disposal.  Any other terminologies, such as IR, or Meta-, 
>> Description etc. needs a concrete definition and could be used either a 
>> small sub-system of the Web (hence making it unsuitable as a generic 
>> design pattern for the Web) or someone needs to come up with a model 
>> that making these concepts an essential component of the Web.
>>
>> I wish this clearly outlined my position (so I won't be accused of 
>> refusing to understand other's position).  Hopefully, it can also give 
>> us a reasonable guideline for the subsequent debate if any.
>>
>> Xiaoshu
>>     
>
> Stuart
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Received on Friday, 27 February 2009 14:15:06 UTC