Initially conceived in the
U.S.A. in 1969, during the cold war, for the benefit of a military
preoccupied by an eventual rupture of communications, the Internet
was immediately used by research bodies and universities, in order
to exchange their ideas. It was with this perspective in mind
that the World Wide Web was created, to support a hypermedia dedicated
to building information servers on the Internet. Created in March
1989, on the initiative of Tim Berners-Lee [Berners-Lee 94] for
the community of physicians at the Centre d'Etudes et de Recherches
Nucléaires (CERN) in Geneva, its aim was to centralise
scientific results, publications and documentation. The Web was
destined to be a great success and was transformed into a cultural
and social phenomena when, in February 1993, Marc Andreessen of
the National Center for Super Computing, University of the Illinois,
U.S.A., edited the first version of NCSA Mosaic [NCSA 93]. This
graphical interface and Netscape will greatly accelerate the development
of the Internet. The Internet already has millions of users and
will soon be affordable to the average household and, and as a
direct consequence, it is attracting the interest of companies
throughout the world.
As the Web has been completely
successfull, due to the fact that it retrieves information in
a quick, powerful and intuitive manner, the approach and the technology
used, especially the hypertext, will become well known. Unfortunately
though, the concept of hypertext has been simplified. In order
to understand how this concept could lose some of its original
meaning, it is necessary to take a fresh look at the precursers
of hypertext and describe their motivating factors. This will
facilitate the presentation of 'Nestor', a prototype hypertext
for the Web that we have developed for CNET[1]
at Lannion, one of the main research centers of France Télécom.
The names of Vannevar Bush,
Douglas Engelbart, and Theodor Nelson invariably get mentioned
when the recent history of hypertext is under discussion. Indeed,
the projects Memex [Bush 45], Augment [Engelbart 68], and Xanadu
[Nelson 88], that are expressions of new ideas or concrete realisations,
have been crucial to the development of this research domain.
It is necessary to lament
the absence of Paul Otlet from the aforementioned group of scientists
because this Belgian author exhibited in his work [Otlet 34],
11 years before Bush, an exceptional clairvoyance bordering on
prophecy . It is for this reason that this section uses the ideas
of these four pioniers of hypertext to exhibit three essential
elements that characterise and justify the fact that the word
'hypertext' means etymologicaly 'more than' 'text'.
Noting that the number of
books and documents increases every day, [Otlet 34] proposes,
in order to confront this deluge of information, the creation
of 'bibliology', a science and general technique for documentation.
The creation of this science would necessitate "a set of
interlinked machines" having to perform seven operations
of which "the establishment of documents in such a manner
that each piece of data has its own individuality and in its relations
with other data, it must be called anywhere that it is required"
(operation 3) and "automatic access to consulted documents"
(operation 6). It is obviously possible to note that these four
authors shared the same preoccupation : the organisation of literature
on a large scale, support for knowledge accumulated across the
centuries, in order to make access easy and quick to that which
is being manipulated. Within the projects Memex and Augment, the
aim is to help the researchers with their reseach documents. The
aim of the Xanadu project is slightly different, its aim being
the construction of an immense network that takes into account
all the available documentation ever published.
It is possible that these
human and ambitious aspirations are themselves cemented within
the Web. Indeed, the Web plays the role of a global library, giving
its users a flexible and immediate access to a set of documents
that are spread worldwide. Thus, the Web gives the impression
that the user is consulting a unique document although, in reality,
the user is visiting several separated servers throughout the
world. Due to the dematerialisation of documents and abolishment
of the notions of distance and time, the Web offers amazing possibilities,
by using simple electronic clicking, to be everywhere at once.
It should be noted that Engelbart, by the invention of the 'mouse'
and experimentation with multi-windowed screens, has greatly contributed
to an instantaneous and associative displacement within the jungle
of information. In other terms, this displacement inspires, as
wished for by [Bush 45], our natural manner of thinking ("As
We May Think").
[Otlet 34] mentions a second
essential principle for the concept of hypertext. It concerns
the "presentation of documents, either by viewing directly
or through the intermediary of a machine that has to make additional
inscriptions" (operation 6) and the "mecanical manipulation,
at will, of all the recorded data, in order to obtain new combinations
of facts, and new relationships between ideas" (operation
7). Within this outlook, the user is no longer only passive, content
to consult elements of information connected by active links,
but active as well, in the sense that the user has available these
elements in order to add annotations and personal links to them.
This is the reason why the boundary between the author and reader
has a tendancy to disappear since the reader benefits from a freedom
comparable to that of a sculptor who is allowed to model, at will,
using the material that is initially given.
On the Web, a non computer-literate
user unfortunately can not exercise this freedom of action on
the documents. Indeed, the creation of one link for the user,
for example, is neither natural nor convivial because it is necessary
to have minimal knowledge of the following : (i) directories and
files, (ii) text editors, and above all (iii) the language HTML
(HyperText Markup Language) [Morris 95] that is used to describe
the documents. This creation of the relation can be considered
as an important intellectual act since it constitutes, for its
author, an argumentative and rhetorical element.
"The machine that would
perform these seven operations would be a veritable mechanical
and collective brain"[Otlet 34]. "An active community
will be constantly involved in discussion concerning the contents
of its manual"(Engelbart). These two quotations put the
accent on the last distinctive characteristic of the concept
of hypertext, namely the cooperative work that puts the creation
of personalised links and commentaries within the social construction
of knowledge. Due the fact that a hypertext is adaptable and shareable,
this approach means that it is never a final product but remains,
for its users, an area of expression and memory that is constantly
evolving. The hypertext therefore takes the form of a flexible
tool of social communication, at the service of collective intelligence
processes [Lévy 90]. Thus it becomes possible for each
user to have access to all of the knowledge acquired by the community.
At the time of his writing, Bush could already imagine a new profession
of trail blazer who would be the type of experts capable of discovering
and building useful routes within these documents.
It is certainly this characteristic
that illustrates the most the difference between the Web and the
first aspirations of the concept of hypertext. Due to the fact
that the Web is organised according to a client-server architecture,
each author is only in charge of a limited number of documents,
of which the author has sole rights to define the links to other
documents. In other terms, the documents that have not been created
by the author are consultable but communication itself does not
exist, since it is not possible for the user to adjust and transform
them. In this case, it consists more of an interconnection of
distributed knowledge : each user puts his knowledge at the disposal
of the collective and knows that he can access, by return, all
the information that he requires but does not have in his possession
[Nanard 95]. "I offer to others my microcosm of documents"
has substituted the original idea of "Let's share
the universe of documents that we transform together".
It is possible to rename technical
specifications as documents that define the characteristics of
a product or service. These specifications have to comply to certain
recommendations (or standards), namely a set of rules that are
normally created by international organisations of standardisation.
This section describes how as such recommendations have been treated
with respect to 'Nestor', a hypertext prototype that has been
developped for CNET at Lannion.
For the personnel who have
to write specifications, the corpus of recommendations can look
like an encyclopedia. Indeed, these reference documents give,
in the form of english text, information concerning, amongst other
things, definitions, concepts, and examples. The recommendations
form a "microcosm" of interdependant documents and
are structured in the form of traditional linear texts, namely
with a contents page, and a set of successive paragraphs, grouped
in chapters. Containing multiple internal and external references,
specifically to other documents, the consultation of these 'spaghetti
documents' is based as much upon a mechanism of the association
of ideas as it is upon a sequential and chronological reading.
The aim of 'Nestor' is to
transform the set of recommandations into a hypertext for the
Web. It is worthwhile asking if this transformation is opportune,
because, as stated by [Nielsen 90], "just as the best films
are not made by putting a camera in the front row of a theater,
the best hypertexts are not made from text that was originally
written for the linear medium". In response to this objection
it is possible to put forward, in our case, the following two
arguments :
Due to the fact that 'Nestor'
is a hypertext prototype, it should logically display the characteristics
that have been already stated for the gift of ubiquity, the omnipotence,
and the omniscience. These terms were voluntarily emphatic in
order to emphasize the quasi-divine character of the concept of
hypertext, to enable it to be initially defined. In our case,
it concerns recalling the last two founding principles, which
happen to be the most commonplace terminology, of easy creation
of personalised links and team work.
The hypertexts have to, as
their first task, articulate and organise the entities of information
(nodes), by use of relations (links) that exist between these
grains of knowledge. These links are activated by the user in
order to travel elsewhere, according to his interests.
Within 'Nestor', the nodes
represent the formal and logical divisions that can be found in
reference documents, specifically, the contents page, the chapters
and optionally the appendices. Coming from this 'natural' division
of the units of meaning, it is possible to define the following
links :
These links, that could be
renamed as structural links due to the fact that they are directly
derived from logical organisation of linear texts, can therefore
be automatically identified and generated by a compiler. In additon
to these objective links, there are subjective links [Kahn 89]
that are reference links created by the users in order to enrich
the initial connectivity of the hypertext. This category of personalised
link is important for hypertexts as it gives the possibility of
adding links that transform, in a certain way, each reader into
a potential author. Thus the user can, in concrete terms, structure
and build his own knowledge. Indeed, as time progresses, the user,
by interacting with the hypertext, acquires an understanding of
the domain under exploration [Yankelovich 87]. The hypertext therefore
becomes, for the user, a depositary of expertise, a way to organise
his knowledge by correcting and completing, through the creation
of personalised links, the incoherencies and deficiencies of initial
texts. It should be noted that, in our case, only the addition
of links can be performed, since the number of nodes is, by definition,
constant as it is determined by a finalised set of documents.
Therefore, it is possible
to say that, in the first instance, the user appropriates the
knowledge of texts through the use of structural links. It is
only later that he reappropriates this knowledge through the use
of personalised links. In order to explain the semantics associated
with a personalised link, the user can add 'commentary' details
to augment the anchor and the node of destination. Due to the
fact that the 'commentary' and 'destination' details are optional,
the personalised links found within 'Nestor' can be classified
as one of the following three types :
| Direct links (DL) | ||
| Commented links (CL) | ||
| Simple commentary (SC) |
In the case of the link with
commentary, the term 'link' is used even though it is not a real
link, due to the fact it does not relate to two nodes of the hypertext
but to a node that is connected to a commentary page (this is
the reason why the acronym 'SC' signifies 'Simple commentary').
A personalised link is public or private. The public link, in
opposition to the private link, means that the author's work can
be accessed by other users.
The Web uses the CGI (Common
Gateway Interface) [Mc Cool 94] that serves the purpose of writing
the bridges between the information HTTP servers (HyperText Transfer
Protocol) and external programs. The role of these programs, that
are commonly known as scripts, consists of : (i) capturing the
parameters entered by the user, (ii) manipulating them and, (iii)
giving a result to the client program that made the request. The
architecture chosen for 'Nestor' is based upon the coupling of
Matisse[2],
an objet oriented database, and Netscape, a client of the Web.
The interfacing of these two applications is assured by scripts
written in Python, an objet oriented programming language developed
at the 'Centrum voor Wiskunde en Informatica' (CWI) of Amsterdam
[Van Rossum 93].Matisse is a system
used for the managment of object oriented databases. Its basic
concept is the PDM model (Property Driven Model), developed at
the University of Technology of Compiègne [Barthès
et al. 86]. This model is based upon both semantic networks [Quillian
68] and frames [Minsky 74]. An object is characterised by two
different properties : the attributes and the relations. The notions
of minimal and maximal cardinality are associated with the relations,
as occurs within the Entity-Association data model [Chen 76].
From a practical point of view, it is possible to note the following
:
Python is an interpreted programming
language that proposes objects and high level operations using
a simple syntax that is based upon indentation. In addition, it
has the advantage of possessing a standard 'CGI' module that allows
the easy capture of parameters from a HTML page. The following
modules have been written for 'Nestor' :
Matisse
Within this module are the
main functions (written in C) of the Application Programming Interface
of Matisse.
FormatHtml
This module embodies a part
of the HTML language. This language is used for the diffusion
of documents by Web servers and consists of a set of formatting
commands.
Compiler
The compiler allows the transformation
of the set of ASCII recommendations into HTML files. This transformation
is performed in two stages. Firstly, the compiler identifies the
units (or nodes) of the hypertext, more specifically the contents
page, the chapters, and the appendices, and gives them an identifier
(number of nodes) that will be strored within Matisse via use
of the 'Matisse' module. Secondly, the compiler segments these
units in order to physically generate HTML files by use of the
'FormatHtml' module. This generation constructs the structural
links and prepares, for each node, the options that will permit
improvement (cf 'Personnalisation' module). It is easy to understand
why, for reasons of security, the 'Nestor' option that uses the
compiler is safeguarded by a password.
Personnalisation
This module offers the possibility
to the users of improving the recommendations by the intermediary
of annotations, key words, and especially personalised links.
In the latter case, the user can have, at any moment for the current
node, a snapshot of all the public personalised links that the
group possesses. In the same manner, the plurality of viewing
points on a anchor must be taken account. For instance, the following
expression : Anchor (Cl) (Sc) (Dl) indicates to
the user that :
The 'Nestor' prototype has
been recently experimented in a real environment. Two types of
ASCII documents were compiled, namely, a set of recommendations
for CNET and documentation dedicated to the Python programming
language. The results of the two compilations are given in the
following table :
| Number of documents | ||
| Number of bytes | ||
| Number of pages | ||
| Number of nodes | ||
| Number of structural links | ||
| Number of reference links |
We are currently looking for
people willing to test 'Nestor' in order to gather comments about
its running and its ergonomics. The adaptability manifests by
the fact that the user enriches the hypertext via his own knowledge.
In the notion of adaptivity, the hypertext system takes the initiative
by proposing links that might be relevant to the user. In order
to find such informal links, a neural approach, based upon the
Hopfield model, is currently under development.
Literature References
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: Extracts from "Traité de documentation, le livre
sur le livre" taken from "La Pensée",
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[Quillian 68] Quillian, R.
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Special thanks to (i) CNET,
for funding the project, (ii) Jean-Pierre Poitou (CREPCO, University
of Provence), the first person who advocated Paul Otlet 's writing
to us and (iii) Darren Millward, for his precious help during
the compilation of this English version.