Supporting collaboration in distance learning a platform

Document Sample
Supporting collaboration in distance learning a platform Powered By Docstoc

Supporting collaboration in distance learning : a platform
                           evolution in two steps

Richard Faerber
Université Louis Pasteur
ULP Multimédia
16 rue René Descartes
67080 Strasbourg cedex
tel : (33) 3 88 41 66 78

Euro-CSCL Thematics
Collaborative environments for academic learning and teaching (Virtual campuses)
Problem-Based Learning
Technologies for building CSCL environments (architectures, ontologies)


This contribution describes the evolution of the Distant Education environment in higher
education formations delivered at Louis Pasteur University (ULP) (France). We initially
present the pedagogical framework founded on collaborative learning as laid out by the
educational team and we justify it. We present its results when it was put to the test through a
first Distance Learning platform. Constituted around a Web site, a groupware, chatrooms and
discussion forum, this device enabled us to check our pedagogical choices and to note the
lacks of an arrangement, whose elements are not interoperable and the tools often duplicated
and insufficient concerning time organization.
The lessons of this first experiment led us to envisage to use an improved platform. After
having noticed that no commercial product could satisfy our pedagogical requirements, we
decided to design and produce a new Web - based platform in adequacy with our pedagogical
framework. The last part of this contribution presents the facilities and the interface of this
new platform integrating all communication, coordination, cooperation and production tools
at the faculty's and learners disposal.

CSCL, Distance learning, Learning situations, Learning environment, Virtual seminar,
Metaphor, Awareness

Pedagogical framework and Distance Learning platform

Preliminary observations

In 1998 when it was decided at the University Louis Pasteur to put formations at distance, we
wanted to benefit from this opportunity to try out group pedagogy. The pedagogical
framework which was founded at this time wanted to take into account the following elements

   The first reason of giving up distance learning lies in the isolation feeling that learners
    experience when they are distant.
   The natural tendency of a learner which feels alone is to personally challenge the teacher
    or the tutor he knows, involving him in a person to person teaching situation. The dual
    relation teacher - learner is economically insupportable because it mobilizes enormous
    human resources and leads to constant repetitions. The mutualization of information is
    necessary so that a mass Distance Learning system can be economically viable.
   The theoretical work of these last decades in Educational Sciences shows the social
    context within learning. [Me 93] [Me 95] [Jo94] [Pi 74]
   Teamwork in the contemporary company is a reality. The Distance Learning public, often
    made up of adults practicing a profession, is or will be implied in group processes on his
    workplace. If he does not practice a profession yet, an initiation with behaviors and social
    competencies could be made profitable early or late in the world of work.

Taking into account these elements in our reflection for Distance Learning platform
development, we privileged collaborative learning rather than a strategy centered on
knowledge transmission. By forming training groups where the learner is able to build
knowledge, we argue it is possible to try to palliate loneliness by putting him in a situation of
interdependence and interaction with others learners. This situation tends toward taking the
drama out of the difficulties. We estimate that the motivation of the student can be increased
when one calls upon his sense of responsibility and when he knows that the progression of the
whole group will depend on its own work. [Di95]
Using group pedagogy, information, production may be mutualized. Information sharing
reduces in a significant way repetition, whether it is the tutor's or the learner's.

To implement collaborative learning we decided to institute virtual seminars and bring
learners to develop personal projects. From a technical point of view this implementation
proceeded in two successive stages. First, we worked out a Distance Learning platform with
non integrated tools. Then, in the light of experience accumulated during one year of training,
we made the decision to produce a new platform which takes into account of the difficulties
tested in the first one. Initially, we will describe the virtual seminars and define the personal
project of the student. Then, the points which proved to be delicate at the time of the first
experiment will be reported and finally we will describe current platform underlining the main

Virtual seminars

A tutor distributes seminar registered learner in small groups(teams), not exceeding six
people. Designated to help the teams for which it has the responsibility, the tutor submits
them learning situations (also called situations - problems) [As 94] [Fab99] [Ch 99] which
vary according to group composition or seminar objective [Ab 96]. These situations are
concrete and result from real life or professional problems. They are fundamentally intricate
and transversal. It is not a matter of application exercises of the course but of open and
contextualized questions which make sense [As 92]. Knowledge to be implemented may be
multiple, multi-field or scattered, but obviously also in relation to the contents. The results to
be found are not unique, the solutions may be plural according to the point of view of each
one. In the virtual seminar the tutor has a function of facilitator who proposes guidance,
resources, and information which must allow learner to build their knowledge.
In the first phase of the installation of our distance formation device, it was the tutor who
conceived himself the learning situations according to knowledge and competencies to be
acquired by the team members. But worrying for more rigor and flexibility, this task is no
more his responsibility today. Indeed, when the faculty is itself geographically spread out and
when the same seminar may be led in parallel by several tutors it becomes difficult to
harmonize the activities. We thus gave the faculty members who design course contents, the
task of creating and editing learning situations. These situations are put at the disposal of the
tutors who will choose those which are best appropriate to the teams, to their working
conditions, and time assigned for the seminar. Proceeding like this allows a better control on
the nature of learners' activities and alleviates the tutor's tasks

      Learner                         Team n°1       Learner           Learner
                                                Belongs to…
     Acceed to…                  Collaborates                         develops …

   Course unit                            Virtual seminar            Personal
   Course contents                     Learning situation n°1
   Resources                           Learning situation n°2
   Vidéo, animation, pictures,
   quizz                                                             pilote
                                       Learning situation n°3

               realizes …
               Technical team            selects …                       helps…
                                                 Tutor                 Tutor

                                         Formation manager

  Figure 1 This diagram shows the roles of the different members in the educative

 Personal projects

 In addition the device plans for the learner to carry on a personal project developed during all
 the formation period. This work is centered on the concern of each learner and requires
 support of a tutor, collaboration between peers or the recourse to experts usually external to
 the educational community. Knowledge built in the virtual seminars should be directly
 invested in personal project development. The nature of collaboration within the framework
 of the personal project is of different nature compared to the preceding one : the concept of
 group is much more flexible there. It 's the learner, in collusion with its tutor who surrounds
 himself by human resources that he varies according to his needs.

 Deployment of virtual seminars

Learners registered with a seminar session are about ten. They are divided into three teams
which collaborate separately, each one having its own workspace. The tutor who is
responsible for team constitution can take into account in its choice of the specific requests
coming from learners or arrange the composition according to their competencies, their
assiduity, their geographical origin. These workspaces are accessible by mean of a web
browser by the only team members and their tutor. Consequently, for a given learning
situation, each tutor circulates between three workspaces (three teams) to observe, to take part
in documents evolution, in asynchronous discussions, and to propose his assistance. The
fundamental principle is the mutualization : all that is expressed, written, or drawn is shared
regardless of the collaboration tool which is used (email, discussion, talk, vote....). This
asynchronous collaborative work is certainly the most important feature in knowledge
building inside the seminars. It takes into account the different private or professional
obligations of the learners, of the technical difficulties (network breakdown) they encounter in
countries where operators' liability is not always as great as ours, and of alternation of
reflexive/collaboration periods.
Synchronous work is carried out by means of chatrooms. At the beginning of a formation, it is
the tutor who usually plays the role of moderator during the chat. At this time, students are not
yet used to chatting rules and discussions are rather ofteninterwoven. With each meeting, a
secretary is designated to save the talk and put it at the disposal for the absent ones, the
latecomers or simply for later reference. Actually its not possible to utilize chat as knowledge
delivery as in a traditionnal face to face lesson. Sentences must be short, concepts which are
to be developped can not be too complex. The real utility of chat lies more in its
psychological characteristics because it emphasize proximity in the team.
The meeting invitations which emanate from a team member are made available for the other
members by two channels : electronic mail and the deposit of a specific document accessible
by the invited members who may then decline it or accept it. Thus, this doubled information is
on one hand, "pushed" towards the user and on the other hand put at the user's disposal who
can also go to consult it on the spot.
The same informative strategy ("pushed towards... " and " fetch….") appears effective for all
the workspaces related documents or events in a team. Indeed, each member daily receives an
Email report which details the elements which were read, modified, or created by the others
the day before.

At the beginning of formation, it is strongly recommended for learners to consult daily (at
least) their electronic mail and connect to their workspaces as often. This is the way by which
we want to ensure they should not go past collaboration news.
In spite of this precaution, it proved that on average the time elapsed between information
availability on the platform and its reading by the team members does not go down under the
bar of 48 hours, which is a significant factor in the time management and asynchronous
collaboration inside the virtual seminars. Even if all the documents or discussions are not of
equal importance, this value shows that in a seminar time flows strangely : the immediacy
doesn't exist.

Lessons of a first experiment

The first Distance Learning experiment can be considered from both pedagogical and
technical point of view.

Technical point of view

The first Distance Learning platform at ULP [Fa99] consisted in a aggregation of some turn-
key products (fig. :2) : their common point lies in a sole use of an Web browser. This
simplifying choice for the user proved perfectly operational even if in some rare cases one had
recourse to a specific client (ex: Ms Netmeeting). A member of the learner community or
faculty reaches an Internet server. The site is used as a "turntable" for access to :
   administrative information of the formation (HTML pages)
   freeware download (browser software, Acrobat Reader, NetMeeting...),.
   three commercial products:
    a groupware (BSCW)
    a forum of discussion (Dnews)
    Chat rooms (Volano chat).

The virtual seminars proceed using the groupware (fig. :2) which makes it possible to
communicate, coordinate tasks and share files [CEW 94]. The product chosen for the first
platform (BSCW) is founded on an "office" like metaphor and represents inside the browser
window a set of folders. These may imbricate and contain files of any type, URL, or articles
(threatened discussions).

       Learner                               Servers

        Browser                                                             Groupware
                                          Web Server

                                            Information                     Forum

                                          NetMeeting                        Chatrooms
       MS NetMeeting                                                        Volano

    Figure 2 Organization of software on learner and server side

As experimenting this platform, certain aspects appeared difficult to control for the users. In
particular, the way it is composed of disparate software elements causes a interface and
metaphor heterogeneity. This lack of unity contributes to increase the difficulties of platform
discovery and delays the effectiveness of the users.
On this first platform, an operation may be carried out of different manners with different
tools duplicated in several places. This choice, this obvious liberty leads to behaviors that, if
they are the fact of the teacher, are felt by the learners as an organizational lack in the
So faculty members who want to give access to course contents have two possibilities :
deposit their hypertext documents (HTML Pages) on a FTP server or upload them to the
collaboration workspaces. From the point of view of the learner, this makes an access
difference which is not well understood and adds confusion.
In the same way, the organization of the workspaces (folders) inside the seminars may be very
different from one tutor to the other. They have any latitude to multiply, diversify, name these
spaces to their own way. The different strategies implemented by each tutor could faze
learners and harm an easy and clear orientation.
Thus each seminar has a different workspace structure. It is not possible to harmonize these
structures with BSCW because each tutor occupies the offered space of freedom.

In this context of juxtaposition of tools, it is not possible to manage coherence between
proprietary system even if they are open. A platform which consists of a mosaic of software

cannot consolidate information entered in one soft and update it in an other. The lack of
interoperability constitutes a significant slow down for using this first platform. This feature is
particularly remarkable in time management, which is fundamental in distance education
based at the same time on synchronous and asynchronous work.
Thus, the on line diary indexing the seminars periods, the deadlines for work submission, the
meeting data (room, date, device….), cannot be consolidated automatically by the tools of the
collaborative BSCW workspaces. The manual data entry of events or appointments must then
be carried out by a formation manager on request of the interested party. This is a heavy
procedure which impedes to stick to actuality. The delay between request and information
entry may last more than 24h which is definitively too much to keep an animated formation.

Pedagogical point of view

The learner who discovers the platforms facilities is surprised initially because he is
accustomed to see his navigator delivering inert information, whereas here, he can act on the
documents, copy them, modify them. At the beginning of the formation the majority of them
are accustomed " to consume " information. They discover a new characteristic of Internet :
they can act dynamically on shared information.
This passage from a passive role to an active way of thinking, the possibility of sharing its
production, its ideas, its points of view is not done without difficulties. The practices forged
by years of electronic mail marks the minds. It is difficult to make students realize that a
communication practice is insufficient to support collaboration. It is only gradually that each
one understands the communication, organizational or the awareness advantages of a
groupware. The range of the possibilities offered is discovered thanks to the work of the tutor
whose roles in the first time of collaboration, is to favour discovery of new tools.
The beginner uses BSCW groupware like a mass memory (external hard disk) accessible by
his browser. He stores personal information. As he progresses he discovers an environment
which enables him to stay constantly informed of his collaborators' activities, he realizes that
those also have an increasingly fine perception of his own work.
Asynchronous collaboration takes root on the impulse of the tutor. The learning situations
which he proposes at the beginning of the formation are certainly more useful for learning
collaboration than to encourage collaboration in order to learn.
The learner working inside the BSCW workspaces assigned to him, feels free to create new
repertories, to upload documents where he wants, with the names he wants. This may

disorganize seriously the cooperation. It is well known that arrangement is a very subjective
affair and as long as it is a question of ordering documents on a personal computer each one
can find his way in his own classification. But when it is necessary to share such spaces with
several people the situations may quickly become conflictual. After some surprises and
disappointments due to these degrees of freedom offered by BSCW, the tutors were brought
to propose straightaway at the opening of seminars sessions, a folder structure which gives a
solid base for collaboration.

One of the most prominent examples of duplication of functionalities on this first platform
concerns the discussion forum. This platform envisages a general forum which can welcome
all members of the community and allows them to open any free discussion without
moderator. However, the BSCW groupware also allows to engage in discussion forums inside
the workspaces. The general forum, named "Le Café ", was abandoned quickly, since the
learners discovered the possibility to start a contextualized discussion in the very work space
in which the document to debate is laid out.
In addition, we noted how much it is frustrating in this software configuration not to be aware
of the simultaneous presence of others on platform. The impossibility of encountering a peer
in a impromptu way in order to exchange impressions, concerns, information on line, strongly
thwart our intention to break the remote learner isolation.

Description of the current platform : interface and facilities
Like the first platform, the
interface of the new one is
based on the use of a web
browser (fig 3). Its graphical
and functional characteristics
closely        reflect       the
pedagogical              choices
described above.
To stage the principal activity
places    we    developed       a
                                    Figure 3 The browser window is divided into two
composite metaphor which
                                    frames. On the upper left the map give access to
                                    personal office, course contents, seminar room. Down
                                    left pager and organizer. The right frame displays the
                                    shared organizer in the home page

works spatially and functionally.
Orientation and location are possible thanks to a map (left) which lays out seminar rooms,
amphitheaters, an office and a foyer.
The spatial metaphor leads to an architecture which comes in parallel with the three principal
formation axes : delivery of course contents (amphitheaters), virtual seminars (seminar
rooms), and personal projects (office). The Three types of rooms are supplemented by a foyer.
The functional metaphor puts in scene an organizer (time management) and an awareness tool
making it possible to stay aware of simultaneously connected people's presence and identity
and to page them wherever they stay on the platform. These two objects always remain at
disposition wherever one goes as if they where in one's pocket… !

The screen is always divided into two parts (frames) (fig. 3):
On the left, all the accessible places, represented in a map like display. This map depends on
the type of user logged in and the period of formation. For instance, a student will only see the
virtual seminars with which he is registered at a given learning period and the attached course
course units (amphitheaters). The tutor, on his side, may move through the virtual seminars he
animates in the same period. The foyer is the only place seen by everybody at anytime. This
left part of the screen figures the elements of the formation which are of actuality for the user.
The right part of the screen shows the map selected place with its corresponding

                                                      The amphitheater gives access to the
                                                      course contents, objectives, resources,
                                                      prerequisites and syllabus (fig. 4). A
                                                      display board presents the list of the
                                                      students registered at the course unit.
                                                      Near the podium, a room lodges the list
                                                      of the resources, the objectives and the
                                                      prerequisites of the course. Lastly, the
Figure 4 amphitheater gives access to course          projection screen makes it possible to
                                                      visualize the course contents.

The places where the virtual seminars proceed are represented by a set of rooms laid out as
follows: the seminar welcome room constitutes the ground floor (fig. 5), and the rooms which

accommodate each a learning situation are laid out on the floors (3 stages at most).
Circulation is ensured by "staircases"
presented in a tab way. The welcome
room makes it possible to congregate
all the teams working in the seminar
and   is   primarily   intended    for
regulation and coordination of the
training inside the seminar.
On the floor, each team may have
access to a chat which is figured by a
table, to a workspace where it can
upload and share any type of
document (fig 6). We made it               Figure 5 Virtal seminar wellcome room. On top ,
                                           access to different learning situations
possible to associate a threadened
discussion to each document in this workplace. In this way the asynchronous discussion is
thus contextualized. Another feature concerning documents is that each file can be put under
version control in order to follow the evolutions, the successive additions of the team
members [St 99]. The functionality of this type of space thus exceeds the simple file storage.

                                                          The personal project of the student
                                                          is localized in his office (fig 7). In a
                                                          general way, this office is a room
                                                          where all the "private " documents
                                                          are laid out. The arrangement of
                                                          student's office as well as the nature
                                                          of the documents and tools which
                                                          are accessible there differ from those
                                                          from the tutor or the course designer.
                                                          In addition to his personal project,
 Figure 6 Workspace for a team of three learners          the student will find in his office his
 developping learning situation n°1
                                                          personal identity card, his course
notes, his logbook, and his archives which contain the entire past course units and seminars.

Tutor's office enables him to prepare the virtual seminars. It offers the possibility to select
                                                    learning situations among those written
                                                    by the course designer, add information to
                                                    them, or decide on the team compositions,
                                                    modifications, or dissolution within a
                                                    For the course designer the office is the
                                                    space in which are stored the courses that
                                                    it   conceived,    their   resources,      and
                                                    descriptions of the learning situations.
 Figure 7 The office gives access to personal
                                                    If there is one office for each user, may he
                                                    be formation manager, faculty member or
learner. But the seminar rooms and the amphitheaters may be plural : A student may follow,
at a given moment of the formation, several course units and consequently, he can be
registered with several seminars at the same time. The same applies to a tutor, for example,
who can be implied into several seminars at the same time to.

The foyer

The principal function of this place is to gather activities which are common to everyone. It
seemed significant to us that the
learners may find a place to meet (fig.
8) beyond the teams and the groups to
which they belong. Some formations
set up " transverse seminars" supposed
to operate synthesis for several course
units. To some extent these seminars
are actually of regulation nature. The
teachers are absolutely not excluded
from this foyer.
                                           Figure 8 The foyer is intended for common
It comprises                               activities.

   threadened discussions (the bar)
   tables intended for talks (chat)
   a software library providing freeware (acrobat reader, ftp client, image processing
    software, communication freeware, format conversion, demonstrations software quoted
    during formation etc..).,
   a gallery displays significant or remarkable work, or documents giving evidence of the
    learning situations outcomes
   a audio-visual projection place (video streaming) to view punctually invited outside
    contributors or experts conferences.

Time management

Time management is a particularly significant point for a distance formation whose teaching
style is directed towards co-operative learning. Two factors make this management complex :
When the training proceed in group, learners are dependent on each others. They are in the
perpetual obligation to cooperate to organize the progress of the tasks, to coordinate work in
order to respect the deadlines fixed by the tutor.
Parallel to the collective activities each learner must carry out his own time management and
arrange his reflexive work periods according to rhythms imposed by the group or by external
factors with the formation (professional or private constraints).
All that requires a complete and ergonomic tool of time organization which eliminates non-
relevant information for the group itself. Any people belonging to learning community may
enter both private and public data in the shared organizer. The first one will permit to control
reflexive work. To enter public data depends on the place where he stays. The user will
address by default an organizer entry corresponding to people patronizing this place.
Alternation between synchronous and asynchronous activities.
Synchronous aspect of the formation (meetings) requires tools which can make it possible to
all the actors to initially get along over the meetings' dates and the hours, and once the
decision taken, to share meeting information with all those which are concerned. The
organization of these meetings is only possible if people availabilities are clearly displayed
beforehand and if decline/accept invitation is possible before meeting. These functions are
implemented on this new platform.

Asynchronous co-operation rests largely on the definition of due dates. Time organization on
this new platform allows a previsional vision to note impediment , to be forewarned on
opening and end of a learning situation, of a seminar.
For all these reasons, each member of the educational community has access to a shared diary
which informs him of the appointments, the meetings, the various formation periods , and
events. Indeed, this tool which rests on a basis of data, presents the data according to the
logged identity declared at the arrival on the platform This respects security and
confidentiality on the platform. We wanted to give to the diary a row of very first importance
since it is displayed in the homepage opened by default
at the current date. This permits to note immediately the most urgent tasks and commitments.
Based on a functional metaphor one " to organize ", the tabs propose
four sights over time : day planner view, week view, month view and a planning which
visualizes the virtual seminars periods


The new Distance Learning platform described here envisages immediate awareness of
presence and identity of other members of the educational community. They are represented
on the left part of the screen as small icons or avatars. This representation immediately gives
an order of magnitude of the number of persons present on the platform wherever they are. In
a second time the user can ask for of the list of present people (right frame in the browser
window). This list comprises their name, identity photography, electronic addresses, current
degree of availability and it is possible too to page any of these persons if they are available.
Actually everyone can affix on the door of his personal office a panel "not to disturb" which
will prevent others to page him. The same list gives access to the selected users' identity card.
Beside the traditionally informations included in this type of document, one will find there,
the seminars in which the user takes part or took part in the past, his availabilities for
synchronous meetings, the personal web page URL, his time zone etc...


The Distance Learning platform which was designed recently at University Louis Pasteur
takes into account the teaching and technical experience accumulated during former
formations with non integrated communication and collaboration devices. We engaged in an

iterative process of modification and improvement. The pedagogical choices implemented are
maintained in the new devices because they proved to be operative, a detailed attention was
devoted to the insufficiencies and the limits noticed with the use in the previous system. By
adopting techniques entirely founded on on line data bases we could design a Distance
Learning platform which takes into account remote formations management, of the
geographical distributed learners and faculty. This new platform is currently in use within the
framework of third cycle formation in which educational community is distributed in time
zone ranging from GMT + 2 to GMT - 6. This formation just began in fall 2000 with the
partnership of "Agence Universitaire de la Francophonie" and its evaluation will be possible


D’APOLLONIA, S. & HOWDEN, J. (1996). L’apprentissage coopératif : Théories,
méthodes, activités. Montréal: Les éditions de la Chenelière.

[As 92] Astolfi J.P.(1992), L'école pour apprendre, ESF éditeur

[As 94] Astolfi J.P.( 1994), Situation-problème, dans CHAMPY P. et ÉTEVE C.,
Dictionnaire encyclopédique de l'éducation et de la formation, Paris, Nathan,

[Ca 99]. Cameron, T., Barrows H. S., Crooks S. M. (1999) Distributed Problem-Based
Learning at Southern Illinois University School of Medicine, CSCL'99

[CEW 94] Clarence A. Ellis and J. Wainer. A conceptual model of groupware. In ACM
CSCW 94 conference on Computer Supported Cooperative Work, pages 79--88, 1994.

[Ch 99] Cheesman R., Heilesen S. B. (1999) Supporting Problem-based Learning in Groups
in a Net Environment, CSCL'99

[Di95] DILLENBOURG P., BAKER M., BLAYE A., and O'MALLEY C.. The evolution of
research on collaborative learning. In E. Spada and P. Reiman, editors, Learning in Humans
and Machine: Towards an interdisciplinary learning science. Elsevier, Oxford, 1995.

[Fab99] Fabre M. (1999), Situations-problèmes et savoir scolaire, PUF.
[Fa99] Faerber R., (1999) Formation à distance sur un campus virtuel : un exemple. In: W.
FRINDTE, T. KÖHLER, P. MARQUET, E.NISSEN (Eds/Hrsg.). Internet-Based Teaching
and Learning (IN-TELE) 99. Frankfurt am Main, Peter Lang.

[He 99] Hennesy, S., & Murphy, P. (1999). The Potential for Collaborative Problem solving
in Design and Technology. International Journal of Technology and Design Education, 9, 1-

[JJS86] Johnson, R.T., Johnson, D.W. & Stanne, M.B. (1986) Comparison of computer-
assisted cooperative, competitive, and individualistic learning. American Educational
Research Journal, 23(3), 382-392.

[JJSG90] Johnson, D. W., Johnson, R. T, Stanne, M., and Garibaldi, A. (1990). The impact of
leader and member group processing on achievement in cooperative groups. Journal of Social
Psychology, 130: 507-516.

[Jo94]Jonassen, D. H. (1994). Thinking technology: Toward a constructivist design model,
Educational Technology, 34-37.

[Me 93] P. Meirieu (1993). Outils pour apprendre en groupe - Apprendre en groupe ? 2,
Chronique Sociale, Lyon.

[Me 95] P. Meirieu (1995). L'école mode d'emploi, Paris, E.S.F. Éditeur.

[Pi 74] Piaget (J.), préface de Inhelder (B.) & coll., (1974) Apprentissage et structure de la
connaissance, Paris, PUF

[St 99] Stracke J., Amsden J., Goals for Web Versioning WebDAV Working Group

Shared By: