Re: "Authority" of HTTP-based Resource Descriptor

I agree with Larry's position that I summarize as that link constructs could
make assertions about locations of metadata.  I think that the discussion
about authority and trust has grown a little too academic and we should
focus on the real-world use cases.  I still fail to see how the web
architecture prohibits the discovery and link constructs that Eran and Mark
are working on, particularly why a retrieved representation cannot make
assertions about the location of metadata on non http resources - such as
mailto: URIs.

This reminds me of many of the discussions that Roy has led around
representations should be consistent to ensure a consistent world-view
across users, but there's nothing stopping the resource owner from serving
wildly different representations for even the same URI.  It's just that if
they do, they don't get the value of their users having a consistent world
view.  If I see cnn.com as always being about weather and you see cnn.com as
always being about the plant that's in your office, then cnn.com hasn't
gotten the benefit of a consistent world view.

The server gains benefit if all the metadata offered is consistent, and I
don't see any reason to preclude them from making inconsistent assertions.

Cheers,
Dave

On Thu, Jan 22, 2009 at 2:12 PM, Larry Masinter <masinter@adobe.com> wrote:

> I think the problem is trying to use "authoritative" in some absolute
> sense, rather than being explicit that something is only "authoritative"
> according to some "authority".
>
> I think it's easier if you talk about "belief" rather than "truth" when
> trying to design the architecture of metadata. If there's something that
> everyone believes, then you might be able call it "truth" (perhaps until you
> come across someone who isn't a true believer.) But being explicit about
> "belief" makes it easier to reason second-order.
>
> "Trust" is a willingness to accept transitive belief: your trust in an
> authority is reflected in your willingness to believe statements made by the
> authority.
>
> Link headers and Link elements are a way of an information service or
> information object to make assertions about the location of further
> assertions about that object. So if you trust the service or information
> object, then you might also be willing to trust its assertion that the
> location provided is a trustworthy source of metainformation (additional
> assertions).
>
> Larry
> --
> http://larry.masinter.net
>
> (I'm not convinced that it's useful to try to solve these semantic problems
> to bring the web to its full potential, though.)
>
>
>
> -----Original Message-----
> From: www-tag-request@w3.org [mailto:www-tag-request@w3.org] On Behalf Of
> Jonathan Rees
> Sent: Thursday, January 22, 2009 8:46 AM
> To: Eran Hammer-Lahav
> Cc: www-tag@w3.org
> Subject: "Authority" of HTTP-based Resource Descriptor
>
>
> Thanks for doing this - it looks very good. I have a few other
> comments which I'll send later.
>
> I know you are staying away from discussion of whether the information
> in a resource descriptor is "authoritative", or at least more
> "authoritative" than information found through other means, and that's
> probably a good thing, but I know the question will come up. Until we
> have a consensus theory, I think we have to assume that the descriptor
> is, in general, not authoritative, since authority is always relative
> to what's being said - any particular agent can make only some
> statements authoritatively. For example, a statement that a piece of
> historic writing has a certain author is not up to me; my saying that
> the author is so-and-so cannot be authoritative, because I can be
> wrong. This is true even if I "own" a URI with which the work was
> named and I make the statement naming the work using that URI. You can
> choose to trust me when I say it, and you may be justified in doing
> so; but that's a different phenomenon from an exercise of "authority".
>
> The "in general" is important since particular applications, such as
> OpenID, might choose to take certain bits of information found in the
> descriptor to be authoritative, and that's OK. That's not the same as
> saying *all* the information is authoritative.
>
> I can't say I have a good theory of authority on the web, but in my
> spare time I would like to work on one or hunt one down (if it already
> exists).  BAN logic http://en.wikipedia.org/wiki/BAN_logic might be my
> starting point. If anyone else has any insight let me know. For now I
> wanted to make sure this caution was stated.
>
> Best
> Jonathan
>
> On Tue, Jan 13, 2009 at 1:18 PM, Eran Hammer-Lahav <eran@hueniverse.com>
> wrote:
> >
> > http://tools.ietf.org/html/draft-hammer-discovery-00
> >
> > I have recently published a draft for obtaining resource descriptors via
> HTTP using Link headers, Link elements (HTML, Atom), and Site-Meta [1]. The
> draft goal is to provide a unified view on how to use the three methods for
> obtaining information about resources (discovery). The draft invents very
> little (an extension to Site-Meta allowing it to describe individual
> resources and not just the overall site).
> >
> > Any feedback would be greatly appreciated and can be sent directly to me
> or discussed on the www-talk@w3.org mailing list.
> >
> > Thanks,
> >
> > EHL
> >
> > [1] http://tools.ietf.org/html/draft-nottingham-site-meta-00
> >
> >
>
>