From Linked Documentary Resources to Linked Computational Resources
From linked documentary resources to
linked computational resources
Alexandre Monnin (Paris 1, IRI, INRIA) , Nicolas
Delaforge (INRIA), Fabien Gandon (INRIA)
April 17, PhiloWeb 2012, WWW2012, Lyon, France
We wish to demonstrate that it is possible to
account for the putative transition between a
Web of document towards a Web of
applications strictly from an architectural point
Three (?) main concepts
Assumption: Blogic is
"<can-of-worms> Note, this is about what URIs refer to
when used as logical names, not what they "identify" when
used by HTTP. These are two quite distinct ideas. Typically
(not always) a URI identiﬁes some (source of) data about
what it refers to. </can-of-worms>"
Assumption: Blogic is
Two visions. Blogic and RDF as it is (aka the Semantic
- The Web comes first
- We deal with HTTP URIs
- Resources vs representations
- We deal with URIs as proper names
- Meaning of URIs
Two approaches, not two
- The RDF is one take on the Web, a model,
not as complex as reality.
- "Death by layers": but look, we got those
layers already so we should think about
them! How they relate to the Web (theory of
Resources (my - AM -
- Resources aren't things out there : you don't
need to previously check a thing exists in the
physical or scientific sense of the word to
identify a resource.
- Cannot be accessed, we all know that
("shadows", if that is not a means without an
end what is it ! Anything at all...).
- The resource is what bears on the
representations, what explains why there were
In REST (birthplace)
2. The states of a resource
3. The representational states of the resource
2. Application of the rule
3. Representation of that result
Resources are anything,
" (...) the semantics of what an author identfies".
(Fielding and Taylor 2002)
Just an author ?
In Webarch this idea seems to come from Kripke's idea of
baptism. There would lot to say but let's not discus this
Let's rather find out if what we need is such a model of
Micro, meso, macro.
The micro level focuses on the resource itself and its inner
The meso level is about relations and interactions between
The macro level highlights the causal relations between an
editorial policy of a publisher and the way he manages
his web resources
Micro. More clients.
Many more devices are becoming clients.
"Web servers were originally designed to propose "filesystem like" remote
services. Since the common gateway interfaces (CGI) their structure have
become increasingly complex. Nowadays, servers are able to negotiate with
clients to adjust the response so that most of the content is generated on the
fly. Any Web server is also compatible with at least one programing language
that can trigger the processing of very sophisticated tasks that sometimes
involve other remote services."
Micro. Break the causal
"One of the defined rationale behind documentary
resources is that people have tried to preserve the
causal relation between a reference and an
informational content, because it was constitutive of all
our "real world" documentary reference systems. The
evolution from documentary resource to computational
resource made more obvious that this artificially
preserved causal relation had been broken."
The documentary location has been replaced by a locus of
computation, a space of invocation.
CGI and REST have turn URL into RPC passing
parameters to scripts or web services. Now everything is
(and has always been in a sense) URI which are
identifying protean resources that can turn themselves in
any format required by the client. Such are the
Micro to macro.
As said before, a resource is a formal translation of a
publishing rule but these rules can change, the
implementation can evolve to match a new technological
context, a bug can be fixed, a database can be updated
with fresh data. There are many reasons for Web
representations to change and that is the true
communication power of the Web, an editor can instantly
adapt the whole editorial chain synchronously with any
Through HTTP, any computational resource is likely to
refer to other resources or to communicate with them
• Web services composition and orchestration
• Web Data transformations and Mashup
More than ever, resources are related to each other and
can be nested to create original compositions. Thus,
qualifying the Web as an hypertext seems a little bit
outdated so we would rather talk about hyperprocess.
Macro. Many more roles!
This seems to become clearer everyday.
The authorship model was maybe related to the
"documentary Web". A Web of addresses
and static documents. Not that it ever was
like that but it is the way it looked like and
was thought of and used.
Macro. Many more roles
Too many to mention but a few:
• URI "minter"
• Resource definer?
• Resource publisher
• Service provider
• Information architects
On the other hand, it is more and more difficult for
publishers to ensure a good quality of service throughout
the processing chain. The technological stack and the
processes involved in publishing a resource have become
so complex and so distributed that it is becoming harder
and harder to ensure a strict editorial commitment because
as the Web grows in diversity, this commitment has turned
into a computational one.
Macro. Many more rules
The resource is not the only rule : how individual resources
are distinguished from one another depends on a
publishing commitments. Other rules, more or less
In other words, Web resources are often published as part
of bigger resource sets, that have in common to be named
and managed by the same publisher.
Macro. Many more rules
We consider that an editorial policy can be summarized as a structured
rule set. Some of these rules are generic, some others are specific
and can inherit or be related to broader ones. From this, we assert
that any Web resource formally expresses one of these publishing
rules. In other words, a Web resource is situated at the intersection
of a number of publishing rules.
A URI then gives access to a representational state that is the result of
this intersection and its closure, while it only identifies the most
specific rule involved in generating the aforementioned
From the societal point of view, content publishers whose
main activity was to produce content and to guarantee the
quality of information now have to deal with various new
constraints owing to the specificity of the medium.
The architecture of the Web of data and the models of the Semantic
Web may provide a way to match the diversity of online resources by
means of a framework of metadata designed to annotate Web
resources and exploit the semantics of their schemas to process them
Metadata and their schemas could be the keystone of the new
resource-centric Web applications, their integration and interoperability.
It is conceivable that tomorrow, he who controls metadata on the Web,
controls Web resources, and through them a lot of things.