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Re: Proposal, a new class of Web Names

From: Nathan <nathan@webr3.org>
Date: Tue, 15 Feb 2011 17:00:24 +0000
Message-ID: <4D5AB128.90404@webr3.org>
To: Jonathan Rees <jar@creativecommons.org>
CC: AWWSW TF <public-awwsw@w3.org>, Tim Berners-Lee <timbl@w3.org>
Jonathan Rees wrote:
> Let me see if I've got this:
> The problem (in my restatement of what you said) is that different
> people want to use dereferenceable URIs in different ways. In
> interoperability scenarios they would be seen to be fighting over
> ownership of linguistic territory, and the poor agent stuck in the
> middle attempting to combine artifacts from the two sides (e.g. using
> owl:imports) is going to get wrong answers.
> So the solution is to retract httpRange-14 (and all the other specs
> that say the same thing) - http://example/x instead of always meaning
> the document always means the same thing that http://example/x# does,

With WebNames both the URIs you mention above are equal to the webname

   ( 'http://example/x' , '')

The above uses the primary-ref for the name part, which has the in-built 
meaning of:

   '' isPrimaryThingReferredToInTheNamespace 'http://example/x'

and similarly the namespace 'http://example/x' is classed as being an 
absolute-URI and referring to a (potentially) network accessible resource.

It has the inbuilt meaning which caters for the top right and bottom 
left boxes in http://www.w3.org/2001/tag/2011/02/metadata-arch#slide9

So, the webname ( 'http://dig.csail.mit.edu/breadcrumbs/node/166' , '' ) 
would refer to the "document" which we'd understand as being named 
"Reinventing HTML", that which remains consistent, (not the Representation)

and ( 
'http://dig.csail.mit.edu/breadcrumbs/themes/spreadfirefox/logo.png' , 
'' ) would refer to the image which you see

and ( 'http://iandavis.com/2010/303/toucan' , '' ) would refer to the 
toucan, because the RDF statements say so and because the webname is 
being consistently used to refer to said toucan.

and ( 'http://www.w3.org/2000/01/rdf-schema' , '' ) would refer to the 
RDF Schema vocabulary, because the RDF statements say so and because the 
webname is being consistently used to refer to said vocabulary.

note, all of the above use the primary-ref as the name part, obviously 
one can also use any name within a namespace to refer to things, like
  ( 'http://www.w3.org/2000/01/rdf-schema' , 'label' ) which refers to a 
Property defined by the rdf schema vocabulary.


> and that's defined... how?

Well, it'd need specified as a standard to be "defined" so that it could 
be referenced by the normative text of specs of course..

> According to 3986 you look at the media type and go from there

Which I'd suggest is wrong and needs revised to say that the "fragment" 
part of a URI is used as the primary form of indirect referencing [blah] 
not related to scheme specific processing [blah] fragments must be used 
consistently across representations [blah] media types may provide a way 
to expose locally named things globally so that they can be referred to 
using fragments [blah] for example @id in HTML [blah].

> so for HTML and XML it would mean an element

which I'd also suggest is wrong anyway, it normally refers to that which 
is evoked by giving a certain view of some info described in an html 
document, the correlation to an "element" is merely an indirection hook 
for the machine so it can show the correct view - in another case it's 
the part of a video (media fragments) and in another it's something 
displayed via ajaxy goodness etc. The important thing is for media types 
to provide a way to refer to things in memory/serialization that 
describe or refer in some way to that which is named by the frag, not to 
constrain it to be "an element" (the domain of fragment cannot be 
'element', elements themselves are an abstract concept!)

the above two mini rants are orthogonal though, web names are compatible 
with either view of the URI world, because they're a different class of 
identifier, and their usage maps how URIs are used by humans in a way 
that machines can hook in to and take advantage of.

> (which could never be defined since the empty string is not a valid
> element id), and for RDF would be as 'defined' by the RDF.

indeed, that's a reason for the "primary-ref" feature of web names

> This is nice for those who don't like # because it gives them a way to
> write a # URI without writing the # character, and they don't have to
> bother with 303.

and that's another reason for the primary-ref feature, and webnames 
themselves make dereferencing completely orthogonal to the name (303, 
200, whatevs doesn't matter), but intrinsic to the namespace, since that 
part refers to a network accessible resource.

> In fact I don't see how it differs from what Ian and Harry are saying at all.

it's a different approach, and allowing 200 OK on a non frag URI is just 
one of the (positive) side effects. Tis not the same as what they've 
been saying, rather it's compatible with what they've been saying.

but then I hope webnames are compatible with what /everybody/ has been 
saying, you and I included..

> Those of us who have been using dereferenceable URIs to refer to documents are left in the cold and
> would have to make up a new notation (see my TAG slides).

not at all, webnames cover that too, as covered by the examples higher 
up this reply - no new notation needed, the WebName concept handles all 
of that for everybody, we'd just need RDF, and optionally web 
architecture, to adopt them..

> To me it would seem easier just to keep with httpRange-14 and say that
> dereferenceable LOD URIs actually do refer to documents - specifically
> nodes in the LOD network.

But sadly they don't refer to "documents", does http://google.com/ refer 
to a document in the eyes of nigh on every one on the web? no it 
doesn't, but does http://neurocommons.org/page/WebURIArchitectures ? yes 
it does. Likewise http://dbpedia.org/resource/Toucan refers to a toucan, 
but ironically if you GET it with a browser you'll think it refers to a 
document about a toucan (thanks to the 303+conneg) and a linked data RDF 
client will think it refers to a toucan - httpRange-14 is mismatched w/ 

> The L in LOD  would be a document-to-document relation which is what I
> think that community wants.

I'd have to suggest that's the complete opposite of what everybody wants 
as far as I'm aware.. the whole point of LOD is to be able to have thing 
to thing relations, likewise with the semantic web, LOD just bolts on 
the proviso that you publish those statements on the web (which I 
thought was always the point of the semantic /web/).

will reply to RDFa stuff under separate cover..



> Maybe we say it privately among ourselves, but at least we
> would have a consistent way to interpret combined OWL/LOD graphs.
> I came up with the following yesterday in conversation with Manu
> concerning use of # in RDFa: {Don't write <div id="foo" about="#foo">
> if you're at all concerned that the element [see media type reg.] and
> the thing you're calling #foo might have different properties - use
> different fragids in that case.} If you don't care about inference
> (your own or anyone else's) then of course it doesn't matter which you
> do, so you're happy. If you do, you use different fragids and again
> you're happy. Maybe the same approach would work with dereferenceable
> URIs.
> (1/2 cynical here, but want to explore options.)
> Jonathan
> On Mon, Feb 14, 2011 at 6:15 PM, Nathan <nathan@webr3.org> wrote:
>> Hi Guys,
>> Please do read over the following and let me know what you think - might be
>> somewhat of a different approach ->
>> [[[
>> Problem Statement and Background.
>> The Web has long since provided names as a way of referring to things, from
>> time to time the specification of these names has had to be revised, in
>> order to match their usage on the Web as it evolves.
>> With the rise of the Semantic Web, Media Fragments and Web Applications, the
>> usage of these names, especially http names, has changed to become either
>> inconsistent with the current URI specification or their usage is simply
>> unspecified.
>> A side effect of this new usage, is that various communities have differing
>> opinions on just what a URI can or does refer to, and on how those URIs can
>> be used. This leads to tensions between communities which are trying to
>> converge, and in the worst case threatens the evolution of those communities
>> and their respective technologies.
>> The web communities using these URIs share two common requirements, they
>> need to use absolute URIs to refer to network accessible resources, and they
>> require some form of indirect referencing, frequently turning to fragment
>> identifiers for this purpose.
>> One of the most contended uses of URIs, is when they are used to refer to
>> abstract concepts or things evoked by the processing of representations, for
>> example:
>>  - A thing which is described within a representation, i.e. a person.
>>  - A particular application state or recomposable view provided by the
>> application.
>>  - Some particular scene within a movie.
>> Contentions are usually particularly high when a URI of the absolute-URI
>> form is used for this purpose.
>> In order to address this problem, it is suggested that a new class of Web
>> Names is needed. A class which is disjoint with the current set of names
>> (URIs/IRIs), fully compatible with those names, and which models existing
>> naming conventions.
>> Proposal - Web Names.
>> Web Names provide a web friendly way of referring to things, each WebName is
>> a 2-tuple comprising of a namespace and a name.
>>  WebName  = ( namespace , name )
>> The namespace part of a WebName takes the syntactic form of an absolute-IRI,
>> the namespace typically refers to a network accessible resource.
>> Each namespace has an infinite pool of locally scoped references, within
>> different contexts there often exists a need to expose one of those
>> references, for example:
>>  - a reference to something which is described
>>  - a reference to a particular state or information view
>>  - a reference to a function or a variable
>>  - a reference to a particular time sequence and area within a video
>> The name part of a WebName provides a way to expose these indirect
>> references, the name can take the syntactic form of the primary-ref (an
>> empty string) or a reference (a string consisting of one or more
>> characters), the name provides an anchor to refer to things named within a
>> namespace.
>> WebNames have the following syntax:
>>  web-name     =  namespace local-name
>>  namespace    =  absolute-IRI
>>  local-name   =  [ "#" ] primary-ref / "#" reference
>>  primary-ref  =  0<ipchar>
>>  reference    =  1*( ipchar / "/" / "?" )
>> Since WebNames are 2-tuples and IRIs are strings, the value space of
>> WebNames is completely disjoint with the value space of IRIs, however, the
>> lexical form of each WebName is also a valid IRI, as such:
>>  IRI          =  http://example.com/foo/bar#baz1
>>                  \________________________/ \__/
>>                                  |           /
>>  WebName      =             ( namespace , name )
>> By sharing a lexical form which always produces a valid IRI, WebNames are
>> fully compatible with the deployed web technologies, require no changes to
>> be made, and are backwards compatible with existing IRIs which have been
>> minted/used for the purpose of indirect referencing.
>> Due to WebNames being 2-tuples, they cannot be dereferenced, this serves to
>> null and void many of the most complicated and contentious issues outlined
>> earlier, WebNames have been designed in such a way so that communities can
>> opt-in to using them and focus on converging their technologies rather than
>> trying to answer unanswerable questions.
>> It is often the case that a network accessible resource is configured to
>> provide information primarily about a single thing, for this purpose a
>> WebName consisting of a namespace and a primary-ref can be used.
>> When the name part of a WebName is the primary-ref, then the hash ("#") is
>> optional, such that the WebName:
>>  ( "http://example.com/foo/bar" , "" )
>> can be specified using either of the following lexical forms:
>>  http://example.com/foo/bar#
>>  http://example.com/foo/bar
>> and such that both those lexical forms encode the same WebName.
>> ]]]
>> Still needs work, especially on the text, but I think that's enough to get
>> across what I'm proposing in the meantime. Thoughts and feedback more than
>> appreciated.
>> Best,
>> Nathan
Received on Tuesday, 15 February 2011 17:01:21 UTC

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