Transcript Tools for collaborative e

D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
Tools for collaborative e-activities
G. Adorni, F. Bergenti, D. Bianchi, A.
Poggi, M. Somacher
G. Adorni Università di Genova e-mail: [email protected]
F.Bergenti, D. Bianchi, A. Poggi, M.Somacher, Università di
Parma, e-mail: {bergenti,bianchi,poggi,somacher}@ce.unipr.it
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
Tools for collaborative e-activities
This paper discusses a system to facilitate activities through the
network (e-activities) offering tools for collaborative work,
video conferencing and video on demand. The architecture of
the system is composed by two levels. The first level, called
collaborative level, allows remote users to take part to a meeting
where they can interact with each other via a chatting line and by
sharing the use of different applications. A second level, called
multimedia level, allows a multimedia interaction between the
members of the meeting. Each user must own a microphone, a
CCD camera and an internet connection with a sufficient
bandwidth to support the exchange of audio and video data.
We present some results obtained during research activities
(project meetings, software design and debugging, document
writing) involving people connected from different towns of Italy.
The system was also used in e-learning activities distributed
through a campus local network.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
The Web in collaborative e-activities.
•The Web is assuming a central role in the way people share
information.
•Web browsers are available everywhere and they provide an
environment to integrate different services into a common, easily
accessible, platform-independent user interface.
•The Web has already been adopted as one of the principal media
capable of supporting the collaboration between people.
•Nevertheless, the basic communication facilities that the Web
offers are not sufficient to support an interactive approach to
collaboration.
•The communication needs for which the Web was designed was
about consulting structured documents and was not about
supporting an interactive discussion in a virtual group.
•The available Web technologies are not yet sufficient to
implement the virtual-workgroup or the virtual-classroom
metaphor.
D. Bianchi - Tools for collaborative e-activities
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The System Architecture
•Our system relies on a multi-level architecture.
•We define three levels that differ for (i) interactivity and (ii)
requirements on the user’s multimedia equipment and on the
available bandwidth.
•The higher is the level, the higher is the interactivity that the
system offers and the higher are the requirements on the user’s
equipment.
•The multi-level approach allows the system adapting to the
capabilities of the user.
•We propose a solution that is completely based on off-the-shelf
technology that also domestic users can access with small
investments.
D. Bianchi - Tools for collaborative e-activities
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Coarse-grained architecture of the system
Audio & Video
Data Exchange
Chatting line &
Cooperative Tools
Hypermedia material
& E-mail services
•Users accessing the system through a domestic narrowband
connection can still use the services of the collaborative level.
•Users with a wide band connection (eg. a campus local network)
can also access the highest level and take part to an interactive
multimedial virtual meeting.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
Supporting collaborative activity
•In general terms, a collaborative activity is supported by group
communication, i.e., by an exchange of information among a
group of participants, the collaborators, in a session.
•Collaborators may play different roles in a session and the roles
can change dynamically.
•Collaborators may also join and leave a running session.
•A collaborative platform is required to provide all the facilities
needed to support the dynamic nature of the collaboration.
•A collaborative platform should guarantee the availability of
suitable media for information exchange.
D. Bianchi - Tools for collaborative e-activities
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Synchronous vs. asynchronous collaboration
•A collaborative activity can be roughly classified into two
categories, depending on the information exchange dynamism:
synchronous or asynchronous
•Synchronous collaboration is characterized by a high level of
interaction within the group: all the collaborators share a single
view of the discussion and the information is exchanged when
it becomes available.
•Conversely, in an asynchronous collaboration, the
information is transferred only on demand, thus lowering the
degree of interaction in the group.
•The classic Web communication facility support only an
asynchronous collaboration, mainly because HTTP protocol
rely on a communication model in which the browser needs to
request the information, as HTML pages, from the server.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
The Basic Level I
•Our system supports synchronous collaboration in the middle and
the high level. Nevertheless an asynchronous collaboration was
added, as a basic level, to give access to HTML pages and to e-mail
or news services.
•This basic level was introduced mainly to support e-learning
activities.
•The system presents to the student a course module and its related
tutorials through a Web browser.
•The theoretical part of the subject matter is presented through
HTML pages.
•Linked to the main topics of the key chapters there is a series of
tutorials (guided training exercises), presenting questions and
problems that students are invited to solve offering software tools
and simulating instruments for laboratory activities.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
The Basic Level II
•At the end of each tutorial there is a self-assessment test composed
of (i) multiple-choice, (ii) true/false, (iii) fill-the-blank and (iv) essay
questions.
•While multiple-choice, true/false and fill-the-blank questions are
corrected automatically, the essay questions need to be graded by the
teacher; therefore, if the student can access to an internet connection,
the system automatically sends an e-mail to the teacher with all the
information needed to evaluate the results of the test.
•At the same time, the student can take advantage of the e-mail
connection to write her/his comments and to send questions to the
teacher.
•A news group is used for general discussion.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
Collaborative Level I
• Any collaboration support needs to provide consistency-guarantee
mechanisms to correctly manage the shared information.
• In synchronous collaborative environment, where the collaborators
share a single view of the shared information, consistency is
typically managed by a floor-control policy.
• The explicit floor control policy enables only one group member
at a time to modify the shared document. This modifying privilege
is commonly described in terms of possessing the modification
token.
• The distribution of the token to group members is performed by
means of an intelligent policy supported by the voting mechanism.
• The modification-token holder can decide to submit a document
change to members’ voting before committing it to a documentsession revision.
D. Bianchi - Tools for collaborative e-activities
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Collaborative Level II
• The collaborative level is based on a collaborative implementation of
Java AWT package that we called CollAWT.
• As the collaborative components do not extend the AWT component
services, except for the collaboration support, the application is not
aware of the presence of the discussion group thus providing
collaboration transparency.
• This package is implemented by means of the event-broadcasting
mechanism: whenever a collaborative AWT component generates an
event in reaction to an user interaction, this event is broadcasted to all
group application instances in order to deal with it as if it was
generated by the local user interface.
• Only the token-holder’s components are active, meaning that they can
interact with the user, while all others’ components are passive.
D. Bianchi - Tools for collaborative e-activities
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Collaborative Level III
A text
,
AWTEvent
Application
State
Listener
Event
Service
•Events broadcasting is implemented
by the events channel service which
acts as an events broker.
•After an event is fired by the user
interface, the generated object of
class AWTEvent is serialized and
pushed into the events channel.
•The events channel then broadcast
the received data to all group
applications.
•Once received by an instance of the
collaborative application, the AWT
event is treated as if it was generated
locally meaning that it is passed to
the application.
D. Bianchi - Tools for collaborative e-activities
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Collaborative Level IV
•A user can join or leave a group at any time.
•At login the new member receives an instance of the shared application
while all group members are informed of this event.
•The system supports unanticipated sharing of the application and
latecomers can decide to enter into the discussion in a synchronous or
deferred-synchronous way.
•In the synchronous way, the latecomer is immediately accommodated in
the group with a view of the shared document.
•Conversely, in the asynchronous login procedure, the latecomer is
shown all the changes occurred to the document since its last leaving.
•The shared-application instances are synchronised starting from a
common state and evolving by means of user-interface generated events.
•The deferred synchronous policy is performed by the latecomer’s
application asking the transaction-logging service to play back all events
occurred since its last group leaving.
D. Bianchi - Tools for collaborative e-activities
Multimedia Level
The multimedia level integrates
audiovisual components in our
system to improve its
effectiveness from the point of
view of the communication
among the meeting participants
or in the learning process.
Two different tools:
•A videoconferencing tool.
•A tool for consulting
audiovisual documents stored
in digital format.
Are realized using Java Media
Framework and implements the
floor control mechanism.
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D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
Virtual Teams I
•We have used the described e-activities collaboration and
communication facilities to manage a virtual team. We are
experimenting this tool in research activities. Examples are: project
meetings, software design and debugging, document writing.
•To support these activities we have tailored a collaborative
platform, named JWebTop, that supports sharing of documents and
of Java applications for collaborative work.
•The platform gives to the participant to the virtual meeting the use
of a shared textual and graphical editor, and a web browser.
• The editor allows participants to work to a shared document while
the meeting is in progress, the web browser allows to display HTML
text, or to present slides during a talk.
•We are using this platform for scientific meetings with people
distributed at home/office of many towns in Italy.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
Virtual Teams II
•The collaborative level provides as a communication tool a chatting
line. But the exchange of written messages is very slow and annoying.
To facilitate people communication an audio-conferencing or videoconferencing tool is also provided.
•While a video conference requires a wide-band communication
channel, the audioconference requires a narrow-band, but it is usually
sufficient to guarantee an adequate level of communication amongst
the people involved in a meeting.
•In the user interface of the client application a person can require or
release the floor. The floor request are managed by a FIFO policy. Only
the user holding the floor can use the editor or the web browser.
•On the contrary in the audio conference each user broadcast an audio
stream to all the participants. Voices from different users can be mixed.
It depends on the politeness of participants to regulate the dialog turns.
D. Bianchi - Tools for collaborative e-activities
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E-Learning: Basic Teaching/Learning Scenarios I
•the transmission scenario: related to the empty vessel metaphor (oldfashioned; prevailing classroom teaching and lecturing). This scenario is
characterized by a closed domain, well-defined learning goal, fixed
learning route, instruction and practice, diagnosis of errors and
remediation. The expected outcomes are domain knowledge and skills;
•the studio scenario: related to the constructive agent metaphor (current;
study-house). It is characterized by open or closed domain, well-defined
learning goal, flexible learning route, project-based learning, interaction
with different agents (human or otherwise) The expected outcomes are
domain knowledge as well as social and practical skills;
•the negotiation scenario: related to the situated/distributed cognition
metaphor (post-modern). Characterized by open domain, ill-defined
learning goal, open learning route, argumentation, negotiation and
reflection. The expected outcome regards conceptual changes.
D. Bianchi - Tools for collaborative e-activities
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E-Learning: Basic Teaching/Learning Scenarios II
•A prevailing transmission scenario is mainly reflected in classroom teaching,
lecturing, drill and practice while there is little room for discussion/reflection and
for complex problem solving. It is mainly used to teach and learn domain facts and
rules: transmission. Most of the classical intelligent tutoring systems, mainly
interested in domain and student modeling, fit in this class.
•The studio scenario has more emphasis on complex problem solving, on student
initiative and responsibility on problem analysis and solving method selection,
more emphasis on open tasks (writing an essay, conducting a debate, giving a
talk). Main aim is to teach and learn procedures and problem solving strategies.
The modeling issue moves away from representing the cognitive states of the
individual students to support interactions between users in a situation in
which students have to confront with multiple tasks and multiple source of
information. Our work may be considered as an example of this scenario.
•The negotiation scenario, is based on student directed learning, student defined
problems and solutions, student sharing of knowledge and evolving ideas. It is
devoted to teach and learn meta-cognitive skills, to create new knowledge and to
reflect on one’s understanding. May be promoted by the use of e-activities tools.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
E-learning: an example of courseware
•A campus network was used to give access to a courseware case
study. The system that we realized integrates the Web with the
classic e-learning process to offer students and teachers services with
different degrees of interactivity ranging from off-line document
consultation, to web based document browsing and e-mail
communication, to virtual classrooms.
•The collaborative level offers an application-sharing service to
allow integrating the lesson with experiences on, e.g., simulated
instruments and tools for laboratory activities.
•The multimedia level allows the integration of course materials
with audiovisual documents to be used individually or in the virtual
classroom.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
The campus network
We have two different networks. The
first is the TCP/IP intranet of the
Campus. This network is normally used
for all the activities of the basic and
collaborative levels, i.e., access to the
Web server, to the mail and news
services, to the chatting line and tools
for collaborative work. The Campus
network can support those services that
do not require a fixed bandwidth
allocation. On the contrary, multimedia
service needs a guaranteed wide band
connection to transmit video or audio
data. So, a second network based on
ATM technology connects the video
server with the classrooms and labs.
D. Bianchi - Tools for collaborative e-activities
62 2Mb/ s
A TM
62 2Mb/ s
Campus Net work
V id eo Serv e r
15 5Mb/ s
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The campus network
OLT
62 2Mb/ s
TLO
Campus Net work
Sw it c h
A AL
NT
A TM
ONU
8Mb/ s
0. 7Mb/ s
PC/ WS
Campus Net work
BUILDING "A"
PC/ WS
Sw it c h
PC/ WS
Campus Net work
TLO
PC/ WS
A AL
Sw it c h
NT
8Mb/ s
A TM
TLO
ONU
0. 7Mb/ s
PC/ WS
Campus Net work
PC/ WS
PC/ WS
BUILDING "B"
Sw it c h
PC/ WS
BUILDING "C"
The ATM network connects
the video server with
classrooms and laboratories.
It is supported by a PON
(Passive Optical Network)
with a bandwidth of 622
Mbit/sec download and 155
Mbit/sec upload. The fiber
optical network is connected
with the user equipment
using an ADSL switch which
is also connected to Campus
Intranet (Fast Ethernet).
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
An Example of Courseware: Hyperprolog I
•The campus network was used to give access to a courseware case
study in which the different levels can be implemented and tested. The
subject matter of the module is “Mathematical Logic, Logic
Programming and Prolog”.
•The theoretical part of the subject matter is presented through
hypermedia (which are made of hypertext and other kind of materials as
audiovisual documents, animations).
•The course contains also a number of topics related to artificial
intelligence: natural language processing, knowledge representation,
fuzzy logic, learning, temporal logic.
•Linked to the main topics of the key chapters there is a series of
tutorials (guided training exercises) with questions and problems that
the students are invited to solve.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
An Example of Courseware: Hyperprolog II
•Students can actually try out their answers and solutions by using,
within the browser, an available Prolog interpreter on the server
together with a number of files related to the examples presented in the
tutorials. These sample files can be directly loaded and tried out in this
environment which we called PrologLab.
•Also for the AI topics there are a number of working examples that the
students can try in the PrologLab environment.
•Students can easily switch from the hypertext to the PrologLab or use
both concurrently.
•At the end of each tutorial there is a self-assessment test which the
students can take.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
Collaborative PrologLab
•In order to allow a direct distance interaction between teachers and
students, a collaborative environment has been developed.
•The aim is to realize a virtual classroom in which the teacher can
demonstrate the use of the PrologLab, develop programs interacting
with the students, test the program with the Prolog Interpreter.
•All participants in the classroom have to see the same information on
their screens. Moreover each participant can, in an ordered fashion,
gain control of the collaborative resources end use them. For example
can edit a file, consult a program in the Prolog database, execute a
Prolog query and so on.
•The collaborative PrologLab may also be used by group of students
working to a common project over the network.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
The Collaborative PrologLab Interface
Participants can edit and test programs, use a chat line, enter or exit
session, request or release the floor.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
Collaborative PrologLab Floor Management
•Different floor management policies can be adopted.
•Because our aim, with the collaborative tools, is to
reproduce a lesson, we can assume that the teacher may
decide, on the basis of a request list, which student has the
floor and so have an exclusive control of the application
resources.
•At any time, the teacher can also gain the control of the
floor previously given to a student.
•On the other hand, if the collaborative tools are used by a
group of students working to a common project a more
democratic policy of floor management should be adopted.
•A voter list is maintained to allow collective decisions and
the members of the group can vote to accept or reject a
proposed change to the current program.
D. Bianchi - Tools for collaborative e-activities
SSGRR 2002w
System evaluation I
•Analysis of the students’ patterns of activity by means of system
logs. This analysis will give information about students’ use of the
system, which pages of the text they looked at most, which facilities
they used the most (tutorials, self test, PrologLab, e-mail, conference
area) or which ones they overlooked.
•Effectiveness of the system in terms of the students’ learning
outcomes. This evaluation is based on the results of the final test.
•Students’ attitudes toward the resource. A questionnaire was
administered to the students to assess how much they liked this
resource in comparison with more traditional courses. They were
asked which part of the system they used most and which ones least,
which ones they felt as difficult to use and why.
•The result of the questionnaires were integrated with
the
information gathered during focused group discussions on the topic.
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System evaluation II
•Analysis of chat recording in the collaborative PrologLab can be
used to study the interaction between students in working groups.
•Questionnaires can be used to test the satisfaction of the participants
to a virtual meeting.
•We can obtain information about the easiness of use of the tools, the
effectiveness of the communication with the chat line or the audio
conference or the video conference, the usability at work/home with
different communication bandwidth available.