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Re: When does a document acquire (web) semantics?

From: Mark Wilkinson <markw@illuminae.com>
Date: Mon, 01 Feb 2010 11:05:03 -0800
To: "Jim McCusker" <mccusker@gmail.com>, "John Madden" <john.madden@duke.edu>
Cc: "w3c semweb HCLS" <public-semweb-lifesci@w3.org>, "Eric Prud'hommeaux" <eric@w3.org>
Message-ID: <op.u7gpypzinbznux@dd0710001l.icapture.ubc.ca>
I love this conversation :-)

I have a scrap of paper pinned to the filing cabinet beside my desk that  
says "The World Is Flat -  Mark Wilkinson & Ben Good, in the Pub, May 26,  
2006".  That was the night that I feel I truly came to understand where  
the "semantics" are in the "semantic web".

The upshot of our "flat-world theory" is that RDF/graphs are just bags of  
facts.  A collection of properties attached to things.  From that  
perspective, the "graph" is completely flat.  You then lay an ontology  
over that graph, and the ontology contains the knowledge required to  
interpret those facts and 'give them depth'.  Any number of ontologies can  
be overlaid on that graph, to give different interpretations... and amen  
to that, because we all have our own "personal ontology" through which we  
interpret the facts in the world.

so, from my perspective, the Web does not acquire semantics until I lay my  
personal ontology-of-choice over the data.

Mark




On Mon, 01 Feb 2010 10:55:48 -0800, Jim McCusker <mccusker@gmail.com>  
wrote:

> On Mon, Feb 1, 2010 at 1:30 PM, John Madden <john.madden@duke.edu> wrote:
>
>> We had an interesting call in TERM today. One of the topics I would  
>> like to
>> boil down to the question "When does a document acquire its semantics?"  
>> or,
>> "when does a document come to mean something?"
>>
>> I argued the (admittedly intentionally) radical view that documents  
>> have no
>> semantics whatsoever until a reader performs an act of interpretation  
>> upon
>> the document, which in the Semantic Web world would be the same as
>> attributing an RDF/OWL graph to the document.
>>
>> Even if the author of the document attributes a a particular RDF/OWL  
>> graph
>> to her won document, I argued that this graph is not privileged in any  
>> way.
>> That others could justifiably argue that the author's own RDF/OWL graph  
>> is
>> incomplete, or flawed, or irrelevant, or even incorrect. And the same is
>> true of any subsequent interpreters (i.e. authors of RDF/OWL graphs that
>> purport to represent the "meaning" of the same document).
>>
>> Eric argued a really interesting point. He argued (and Eric, correct me  
>> if
>> I'm interpreting you wrong here), that semantics instead come into  
>> existence
>> (or perhaps *can* come into existence) at the point when somebody  
>> executes a
>> SPARQL query on a set of RDF/OWL graphs. That is to say, maybe I'm  
>> wrong and
>> semantics doesn't even come into existence when somebody attributes an
>> RDF/XML graph to a document; but rather it only comes into existence  
>> when
>> somebody queries across (possibly) many graphs of many different people.
>>
>
>
> Let me put on my Linguistics and Philosophy hats here for a second.
>
> The world of the semantic web revolves around formal semantics as  
> defined by
> monotonic symbolic logic and, as such, means that inferences that are
> created are predicated on a universe where their antecedent axioms are  
> true.
> Within that universe, those axioms and inferences are universally true,  
> and
> cannot be countermanded by further information. So, as soon as a  
> document is
> encoded using axioms of symbolic logic, within the world of semantic web,
> that document gains semantics.
>
> However, this sort of thing only holds within the worlds of formal
> semantics. In linguistic semantics, none of these guarantees are true,
> especially the idea of monotonic statements. One could easily claim that  
> a
> given statement is meaningless (without semantic value) outside of it's
> context, and that any given statement only derives meaning from the  
> context
> from which it was derived. So in the case of the above document, it would
> gain more meaining based on the understanding that was gained through,  
> for
> instance, knowing what actual entities the document refers to. Also, the
> additional capabilities listed can provide some of that context on a  
> sliding
> scale, by providing that context.
>
> Jim
> --
> Jim McCusker
> Programmer Analyst
> Krauthammer Lab, Pathology Informatics
> Yale School of Medicine
> james.mccusker@yale.edu | (203) 785-6330
> http://krauthammerlab.med.yale.edu
>
> PhD Student
> Tetherless World Constellation
> Rensselaer Polytechnic Institute
> mccusj@cs.rpi.edu
> http://tw.rpi.edu


-- 
Mark D Wilkinson, PI Bioinformatics
Assistant Professor, Medical Genetics
The James Hogg iCAPTURE Centre for Cardiovascular and Pulmonary Research
Providence Heart + Lung Institute
University of British Columbia - St. Paul's Hospital
Vancouver, BC, Canada
Received on Monday, 1 February 2010 19:05:09 GMT

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