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

Re: Terminology Question concerning Web Architecture and Linked Data

From: John Black <JohnBlack@kashori.com>
Date: Sun, 29 Jul 2007 23:58:22 -0400
Message-ID: <087801c7d25d$e0437fe0$6601a8c0@KASHORI001>
To: "Sandro Hawke" <sandro@w3.org>
Cc: "Sandro Hawke" <sandro@w3.org>, "'Linking Open Data'" <linking-open-data@simile.mit.edu>, "SW-forum" <semantic-web@w3.org>, <www-tag@w3.org>

Sandro Hawke wrote:

>> And that makes is far less crisp, I'm afraid.
> Yes, sad, isn't it?    For a minute there, it did seem nicely crisp.
>> Sorry, but I still find this incomprehensible, that the text of a book is
>> not an information resource, but if that same text is encoded in a
>> computer
>> file on a web server, it now somehow becomes an information resource. Or
>> what I found just as surprising was when Tim said, "...a literal string
>> is
>> not an information resource." [2] about a text string in a static web
>> page
>> served by a web server, here http://kashori.com/ontology/MyURI. Honestly,
>> I'm not debating here, I just don't get it.
> I hear you.   Sometimes I think I can kind of make sense of it; sometimes
> not.  It's hard to come up with a simple and coherent model for a very
> messy and complex system....    (the real, deployed web is complex
> enough -- try to add the Semantic Web...?)
>> > So, in this metaphor, a URI is something you hand a guide, and the
>> > guide
>> > will show you the relevant spot on a wall.   If you give a URI for a
>> > non-IR, then the best the guide can do is show you a spot on the wall
>> > which talks about that non-IR.  (That is, it can do a 303.)
>> When used by an agent in the context of the semantic web, that URI is a
>> name, used to refer to a resource. Either I know what that agent is
>> referring to by that URI or I don't. If I know what the agent denotes by
>> that name (URI), then I don't need to be taken to the wall at all. Or if
>> I
>> don't know what resource the agent refers to by that URI, then it won't
>> help
>> to be put in front of a stream of representations, because the
>> representations are not the resource, and unless you know the nature of
>> the
>> resource, you can't know whether the received representations reveal that
>> nature or not. And this is true both in the case of information or
>> non-information resources, because the essence of neither can be
>> transmitted
>> over a network, as I argue above. In either case, information or
>> non-information, what I really want to hear is a definite description of
>> the
>> resource and to be told that other agents do associate that description
>> with
>> the name (URI) used.
> Here, when we get close to what's actually happening, and can just talk
> about Semantic Web / Linked Data use cases, I disagree with you.
> Specifically (repeating) :
>> Either I know what that agent is referring to by that URI or I don't.
> That's human-talk, not machine talk.  Machine don't know what things
> are; they just know logical statements about them.  [I happen to believe
> that's true for humans as well, but we don't need to go there.]  So the
> question isn't whether I know what an agent is referring to but what
> logical statements I have (and believe) about the thing being referred
> to.

Yes, I am talking as a human. I think the machines should talk for 
themselves. I agree those logical statements may be necessary for a 
reference to happen, but I certainly don't think they are sufficient. At 
least you must also have made an association between those logical 
statements and the name or symbol used by that agent to refer to that thing. 
What else would connect those - the logical statements you have and 
elieve  - and the name? For a machine, I suppose, it would be a symbol 
table, for a human, a memory. And there is no standard or commonly accepted 
way to establish that link between a URI and a set of logical statements 
that describes the thing denoted by the URI.

> The ability to go to the wall is the ability to (maybe) find out more
> information (statements), probably about that thing, and things it's
> related to.
>> In either case, information or
>> non-information, what I really want to hear is a definite description of
>> the
>> resource and to be told that other agents do associate that description
>> with
>> the name (URI) used.
> I'm not sure what a "definitive" description is.  All you get is some
> statements.  They may be "definitive" in the sense that they were chosen
> by the person who allocated the name.  I'm not sure that's very
> definitive....

If an agent, human or machine, has and believes a set of logical statements 
about a universe of discourse such that there is one individual, and only 
one individual about which all those statements are true, then I say that 
agent has a "definite description" of that individual. If that agent then 
associates a symbol with that set of logical statements, what I am calling a 
definite description, then I would say that agent knows what it refers to 
with that symbol. If the symbol is linguistic, then it has and knows a name 
for that individual. In humans, this link is a form of memory. In machines, 
it is a symbol table of some sort. But both of these are necessary to use
references, one, given your logical statements about a thing, you must be 
able to come up with the name that is commonly used to refer to it, and two, 
given a name, you must be able to retrieve the logical statements that you 
know about it, if you are a human, or that you link to it, if you are a 
machine. Isn't that what naming is?

> As for the association between URIs and retrieved content, you find that
> out by doing a web retrieval....
>> By the way, in the current scheme, where am I supposed to go for a good
>> description of, rather than the direct experience of, an information
>> resource?
> There is no way to do that, with the current web.  All you can do is go
> there and hope it tells you about itself.  Lots of human-readable
> websites do.  Some RDF graphs do.

But then there is no standard or commonly accepted way for an agent to 
identify, name, refer to, or denote even information resources with URI with 
the current web. When you access a URI, you get an experience, not the 
resource itself. So the current web is a system of named experiences, not of 
named information resources. Isn't correcting that one of  the goals of the 
semantic web?


>   -- Sandro
>> > Along this more sophisticated model, one of my prefered terms (instead
>> > of Information Resource) was "Response Point".     But this is all
>> > pretty darn fuzzy, and a hard subject on which to reach consensus.
>> >
>> >   *        *         *
>> >
>> > Really, I think should probably just call them "web pages".   (I know
>> > some people have some ideas about Information Resources which are not
>> > Web Pages.  I'm not convinced.)
>> >
>> > So:
>> >
>> >        Information Resource == Web Page.
>> >        Non-Information-Resource == Anything that's not a Web Page.
>> >
>> > (And while we're at it, call then "Web Addresses" not "URIs".)
>> >
>> > So, one of the funky Semantic Web ideas is to give Web Addresses (or
>> > Pseudo-Web-Addresses) to things which are *not* Web Pages.  Huh?  This
>> > sounds a little weird, especially if you try to call them real Web
>> > Addresses, but via some tricks it kind of works.  It lets you talk
>> > about
>> > things in a way where the listener can find out more information if
>> > they
>> > want it.
>> >
>> > Humans are getting used to this with Google.  If I hear a term I don't
>> > understand, I can often Google it faster than I can ask the speaker to
>> > explain it.  Especially if it's in a written document.  (Of course,
>> > Google just makes it faster and easier -- it's always been possible to
>> > do research.)  Using URIs (pseudo-web-addresses) instead of search
>> > terms
>> > has some advantages and some disadvantages; I think it's a good plan,
>> > myself.
>> >
>> >    -- Sandro
>> >
>> 1. http://lists.w3.org/Archives/Public/www-tag/2007Jul/0112.html
>> 2. http://lists.w3.org/Archives/Public/semantic-web/2007Jun/0265.html
>> John
>> www.kashori.com
Received on Monday, 30 July 2007 03:59:02 UTC

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