W3C home > Mailing lists > Public > semantic-web@w3.org > June 2007

Re: owl:sameAs use/misuse/abuse Re: homonym URIs

From: Ioachim Drugus <sw@semanticsoft.net>
Date: Thu, 28 Jun 2007 15:16:00 -0700
Message-ID: <46843320.50905@semanticsoft.net>
To: Renato Golin <renato@ebi.ac.uk>
CC: John Black <JohnBlack@kashori.com>, Tim Berners-Lee <timbl@w3.org>, Richard Cyganiak <richard@cyganiak.de>, Jacek Kopecky <jacek.kopecky@deri.org>, Bernard Vatant <bernard.vatant@mondeca.com>, semantic-web@w3.org

Hi Renato,

It seems, I see the difficulties you are talking about and I think your 
emphasis on *context*  is the key to help out. But, there are also other 
aspects..

Renato Golin wrote:
> Ioachim Drugus wrote:
>   
>> 1. To distinguish information from data, I follow the principle:
>> Information = Data + Interpretation.
>> Without a content-type I cannot interpret the data - therefore, what
>> comes without a content-type is not information. I believe, in web
>> Architecture, by content type they made a perfect distinction between
>> data and information.
>>     
>
> Hi Joe,
>
> Data contains information that can be extracted in several different
> ways depending on the context (as you said it yourself) BUT the
> content-type is only one of many different contexts.
>
>   
I think, content-type is the type that the *author* of the content 
*intended*  the content to be. Content-type helps the interpreter 
(interpreting agent) to select the right approach to interpretation, but 
does not  guarantee that it will interpret the content as it was 
intended by the author. Availability of content-type is necessary but 
not sufficient for a piece of data to become information.
What I wrote previously refers only to discrimination between data and 
information, but it does not explain how things go further.

Now, since the interpreter is confined by the knowledge {content, 
content-type}, the only other thing which is given to start the 
interpretation process is *context*.

> Other contexts that could apply are domain name, geographical location,
> protocol used, etc. Internal data can also change the context, even if
> your content-type is different.
>
> If you rename a GIF file to JPG it'll still be a GIF and will open as a
> GIF on most programs. In this case, the header inside the file is what
> tells what the file really is.
>
> Content-type is in HTTP protocol and not in RDF or HTML so even if you
> serve a HTML file with content-type "text/plain" a browser can still be
> able to read, interpret the HTML and render a web page for you without
> problems.
>
> In a nutshell: I *can* interpret data without content-type but I
> *cannot* without at least one kind of context (including content-type),
> be it internal or external to the file.
>   
I used the term "content-type" in a wide sense to apply it both to human 
and software agents.  Now, if you, as a human agent, can interpet a 
piece of data, then in my terminology, you have a content-type 
formulated in a language specific to human agents. You could have 
*guessed* it based on data format (your guess might be wrong, because as 
an author, I might have *intended* the data to be a piece of music and 
you took it as text - but this is not the point). I reformulate you 
statement like this - you *can* interpret data with your human specific 
content-type, which you "inferred" from the context, even though you are 
not given the software specific content-type. Another agent, a software 
agent, cannot interpret without the software specific (like 
"text/plain") content-type. So, it looks to me that anyway, a piece of 
data can be interpreted and become information for an agent only if the 
agent has a content-type for it. Content-type looks like a minimum, 
proceeding from which, an agent can interprete the data.

There is yet another aspect - the difference between *information* and 
*information resource* on which I which I will not write here  to keep 
to the point of this discussion - discrimination between data and 
information. This difference is clearly stated in how Tim defined the 
information resource, but I think,  after I work here a little, I will 
come back with a " formalized" manner to put it, which might also help.

Joe
(Ioachim Drugus)
Received on Thursday, 28 June 2007 22:16:06 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 1 March 2016 07:41:57 UTC