W3C home > Mailing lists > Public > public-rdf-in-xhtml-tf@w3.org > July 2007

Re: the Creative Commons take on @href everywhere

From: Mark Birbeck <mark.birbeck@x-port.net>
Date: Tue, 10 Jul 2007 13:32:39 +0100
Message-ID: <640dd5060707100532j75f7b319j4edaea616b0ebe0f@mail.gmail.com>
To: "Ben Adida" <ben@adida.net>
Cc: RDFa <public-rdf-in-xhtml-tf@w3.org>

Hi Ben,

> So, the problem with the above paragraph is that it is basically a
> contradiction of the principles of semweb and RDF, as I understand them.
> If you point to a URI, you don't know ahead of time what it might be.

In a set of RDF triples that is of course true. But we're dealing with
links in HTML documents. I think it's reasonable to say that a URI
that appears in an @href in an <a> in an HTML document is making
reference to an information resource.

> It
> might even change over time, so you shouldn't declare, as the linker,
> that it's an information resource or a non-information resource. What
> if, for example, two pages link to a URI, one of them with @resource,
> the other with @href? Whom do you trust? You have to trust the server
> for that URI, no one else.

This is an odd scenario. We need to remember what a non-information
resource is; it's a URI that is referring to something that we want to
make statements about, but the 'something' being referred to is (give
or take) not a web page. So if I make a reference today to 'something
that is not a web page' using @resource--like a person, a car, a
planet, an event, etc.--I think it's unlikely that at some point in
the future this resource will 'become' a web page.

Of course, it is possible that the URI will get reassigned, but *that*
really would be a problem for the semantic web if it happened
transparently. Hopefully all previous statements about the person,
event or car would be removed to make way for statements about the web
page, and at that point the author can decide whether they want to use
@href or @resource.

Note by the way that I'm not proposing stopping people using one or
the other--as I said before if they get it wrong, so be it. However,
in my mark-up I certainly don't want to use @href to indicate a
resource that is *not* a web page, since I don't want to run the risk
that in the future some browser will allow the user to click on it and
load...well, nothing.

(And I also don't want XHTML 2 spec authors to be told in the future
that we can't allow the appearance of @href on _any_ element to
represent a navigable link, because unfortunately there are too many
non-navigable values in use already.)

> So I really don't think this is a reason to introduce a new attribute in
> RDFa, because at an architectural level, it's not quite right to imply
> that you can declare some property of a foreign resource.

I don't follow this bit. I think I know what you mean, but there is no
'property' to indicate something is an information resource or a
non-information resource--it's merely a convention. So I'm not
suggesting we 'declare' this property.

All I'm suggesting is that if an author knows for definite that they
are referring to something that will never be viewable in a web
browser (like me, or you, or a box of chocolates or a camel) then they
should be able to make statements about it without worrying that
someone _might_ try to load the camel or your or me or the chocolates
into their web browser. (Because currently technology only allows us
to load _information_ resources into a web browser.)

> > Anyway, back to the main issue; all I'm saying is that for those
> > authors who *know* what they are linking to, having the ability to use
> > the @resource attribute is very useful in *addition* to @href. I.e.,
> > it's a way of saying 'I _know_ that the resource that I'm referring to
> > is not an information resource'.
> Again, just to be clear, the point of RDF and the semweb is that, as the
> linker, you *don't* know. Providing a mechanism to express this supposed
> knowledge is, to the best of my understanding, wrong.

But I *do* know. :) I know when I'm making statements about a web
page, and I know when I'm making statements about an airplane. If I
didn't, I'd be in a right pickle. And since I know what it is that I'm
making statements about, then I certainly know that one is an
information resource, and the other is not.



  Mark Birbeck, formsPlayer

  mark.birbeck@x-port.net | +44 (0) 20 7689 9232
  http://www.formsPlayer.com | http://internet-apps.blogspot.com

  standards. innovation.
Received on Tuesday, 10 July 2007 12:32:47 UTC

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