Skip to main content

Full text of "ERIC ED427738: Distributed Education Using the mStar Environment."

See other formats


ED 427 738 

IR 019 289 





Synnes, Rare; Lachapelle, Serge; Parnes, Peter; Schef strom, 

Distributed Education Using the mStar Environment. 


7p . ; In: WebNet 98 World Conference of the WWW, Internet and 
Intranet Proceedings (3rd, Orlando, FL, November 7-12, 

1998) ; see IR 019 231. 

Reports - Descriptive (141) -- Speeches/Meeting Papers (150) 
MF01/PC01 Plus Postage. 

♦Computer Assisted Instruction; *Computer Mediated 
Communication; Computer Oriented Programs; *Distance 
Education; Educational Technology; Foreign Countries; 
Postsecondary Education; Professional Development; Secondary 
Education; World Wide Web 


The mStar environment for distributed education utilizes the 
World Wide Web and IP-multicast to enable teacher- student collaboration over 
large geographic distances. Several educational projects, spanning secondary 
school courses to company internal training have deployed the mStar 
environment. This paper reports on experiences gained over a year of practice 
at the Lulea University of Technology (Lulea, Sweden) and the Center for 
Distance-Spanning Technology. The paper presents the methodology and 
technology used, while recognizing usage scenarios such as preparation of 
presentation material, distributed presentations, asynchronous playback of 
recorded and edited material, and virtual meetings for educational support. 
Contains 11 references. (Author) 


* Reproductions supplied by EDRS are the best that can be made 

* from the original document . 

Distributed Education using the mStar Environment [1] 

K&re Synnes, Serge Lachapelle, Peter Pames, Dr Dick Schefstrftm 
Departement of Computer Science / Centre for Distance-spanning Technology 
Lule& University of Technology, 971 87 LuleS, Sweden 
{Kare. Synnes, Serge.Lachapelle,Peter.Pames,Dick.Schefstrom}@cdt. 


Office Of Educational Research and Improvement 


□ This document has been reproduced as 
received from the person or organization 
originating it. 

□ Minor changes have been made to 
improve reproduction quality. 

• Points of view or opinions stated in this 
document do not necessarily represent 

Abstract: The mStar environment for distributed education utilizes the WWW and IP- official oeri position or policy. 

multicast to enable teacher-student collaboration over large geographic distances. Several 

educational projects, spanning from secondary school courses to company internal training, 

have deployed the mStar environment. This paper reports on experiences gained over a year 

of practice at the Lule& University of Technology and the Centre for Distance-spanning 

Technology. The paper presents the methodology and technology used, while recognizing 

usage scenarios such as preparation of presentation material, distributed presentations, 

asynchronous playback of recorded and edited material, and virtual meetings for educational 


1. Introduction 

The WWW community's strive for content quality has created a quiet revolution in education. In fact, much 
work in this field has been presented at past WWW conferences. The many efforts related to the educational uses 
of the WWW [Perron 94, Goldberg 95, Ibrahim 95] and virtual classroom environments [Lai 95] have been a 
major influence for this revolution. The availability of course related information such as lecture notes, extra 
course material, exercises, and course scheduling blended with the WWW's inherent qualities such as hyperlinks 
and accessibility have added much information to the classical structure of courses. 

Although undeniably useful and valuable, education on the WWW has lacked a fundamental feature: the 
presence of quality video and audio for natural spontaneous interaction. WWW-based solutions such as 'HTML 
courses' for 'electronic-education* have somewhat restricted the exchange of information between students and 
their teachers. More recent technical solutions, such as the use of multimedia in WWW documents, are limited to 
simple playback control, thus leaving no room for spontaneous interactivity. This deficiency has prevented 
broader use of distance education on the WWW, since university courses should offer the opportunity for 
discussions and debate. 

This paper reports on more than a year of research and actual usage of the mStar environment [Pames 97a, 
Pames 97b] in projects aiming to use and demonstrate the full potential of distributed multimedia education. It 
will first present a brief background, then put forward different usage scenarios and tools, and finally provide a 
detailed discussion about experience acquired from usage of this new education environment. 

1.1 Background 

Bringing quality distance education and collaboration to the Internet is one of the driving forces behind the 
Centre for Distance Spanning Technology, CDT, at the Lule& University of Technology. Many high schools 
cannot gather the critical mass and competence to offer the courses and subjects that are possible in the more 
densely populated areas. By giving WWW-based courses over the networks, a sufficient critical mass is 
generated, creating a county-wide virtual university with breadth and quality that might otherwise not be 

Furthermore, the funds per student are continously decreasing, where the resources left available will have to 
be used more efficiently. The normal way to compensate for funding cuts is to create larger student groups. An 
efficient solution to manage these bigger groups of students is having a more teacher-independent 'virtual student 
community', where students can collaborate in solving problems. This may reduce a teacher's increased workload 
due to bigger classes. 

[1] The paper is also available in HTML as a frill-length research report: 


G.H. Marks 


Giving WWW-based courses and creating a virtual student community is made possible thanks to a unique 
Internet engineering project, IT Norrbotten, which has built a multicast enabled high-speed network 
infrastructure between communities and companies in the county of Norrbotten. Together with the University 
campus network, this has created an excellent communication framework for distributed education. 

The Lule& University of Technology has given a number of courses using the mStar environment, ranging 
from graduate-courses to full fledged under-graduate courses. The first course using the technology was about 
the technology itself, Distributed Networked Multimedia. About 110 under-graduate students followed the 
course together with an additional 30 students from the county area. Other under-graduate courses have been 
given using the same methods, such as a course in Object-Oriented Programming with more than 120 students. 
All of the graduate courses at CDT have been conducted using the mStar environment as well. Therefore, the 
University has achieved a significant deployment and usage of distributed education over the Internet. 

Today many large companies, such as Telia and Ericsson, are showing a growing interest in the technology 
as well. Several courses for the companies have been given using the technology, and the Ericsson deployment is 
progressing rapidly. Giving joint courses might help bridge the gap between local industry and the university. 
mStar is used for courses and presentations as well as traditional meetings, thus reducing the need for travelling. 

This paper therefore presents the concrete results of a wide deployment effort of the mStar environment for 
distributed education where secondary schools, the university, local companies and communities are all active 
participants. By now a large amount of persons have tried the mStar tool suite for education, with varying degree 
of satisfaction. We are now only starting to see the first social and cultural changes within the schools and 
companies involved. 

2. mStar Distributed Education Scenarios 

The mStar environment is used in a number of education related scenarios, which today is used to give real- 
time interactive courses. 

2.1 Preparation of Presentation Material 

The first scenario is one of preparation of a lecture’s content, which involves preparation of traditional 
presentation material using HTML. The benefits of HTML for an overhead medium are numerous: 

• Traditional WWW hyperlinks that point to more information can be inserted in the slides. 

• Users viewing these slides on their desktop computer can control the document’s window size, font sizes 
and colors. This can greatly help people with viewing disabilities. 

• HTML is a very portable format that is widely supported across numerous. 

• Multicasted HTML slides uses very little network bandwidth in comparison with video captured slides. 
With the help of SlideBurster, the teacher can divide a single HTML document into a number of different 

slides. The tool automatically creates links to each of the slides and creates an outline for the lecture. Once the 
slides are ready, the teacher can publish the slides on the course’s WWW pages before each lecture. Overall, this 
step helps the students to prepare for lectures as well as enhances the quality of the class material thanks to the 
many hyperlinks to related material. 

2.2 Distributed Presentations 

Once the course material prepared, the teacher or a class technician must go through a number of steps: 

1 . For students to ’tune-in’ to the lecture, the MBone session must first be created and announced on the 
WWW. This is done via the WWW-based session directory mSD (multicast Session Directory), and 
mAnnouncer (multicast Announcer) [Pames 97a p.4]. 

2. Once the different media sources are being transmitted, a tool called mVCR (multicast VCR) is used to 
start recording on the mMoD (multicast Multimedia on Demand) server [Pames 97a p.7]. 

3. During the lecture, the technician can remotely control positions, zoom and focusing of the two cameras 
inside the lecture hall with the help of mDirector (multicast Director) [Pames 97a p.9]. The cameras are 
used together with video grabbers to digitally capture the audience and the teacher. 

The audio and video streams are sent throughout the network using IP-multicast [Deering 91]. The students 
can 'tune-in' to the appropriate lecture by pointing their browsers to mSD's WWW page. mSD’s main purpose is 
to present an interface to available sessions. From mSD students can launch the proper tools, such as VIC (Video 


Conferencing Tool)[Jacobson 95] for video, mAudio (multicast Audio) [Pames 97a p.5] for audio as well as the 
other mStar tools. This simple step is critical since only limited technical knowledge should be required to fully 
take part in a session. Hence, a lecture is never more than ’a few clicks away’. The participant is then 'submersed' 
in an environment that takes distance education a step further from traditional HTML-based courses. 

The student is no longer a passive receiver as he can interact in real-time. Students participating physically in the 
lecture hall can hear questions asked by online participants through the audio system and see the online 
participants through a projection on a wide screen. Naturally, they are also heard by all other on-line participants. 
This creates a very symmetric environment for two reasons: 

1. All participants has access to the same facilities and can participate equally in discussions. We feel that 
this is a very important feature for promoting student participation and debates between class members. 

2. The delivery of all the multimedia content is achieved through IP-multicast, which substitutes the 
traditional client-server structure for a symmetric method of delivering multimedia content. 

As the lecture progresses, mWeb [Pames 97a p.39, Pames 97c] is used to synchronize the teachers' WWW 
browser with the participants browser windows, thus working as a distributor of presentation material. This 
greatly improves the overall ease of use as well as the lecture’s natural flow for the on-line participants. The 
mWeb is an important part of the environment; therefore it is extensively described in section 3. 

Meanwhile, a participant can interact with the teacher and the other participants by raising his hand using 
mWave (multicast Wave) [Pames 97a p. 17 (was mW2T)], thus imitating the social protocols of a normal 
classroom. Participants can also use mChat (multicast Chat) [Pames 97a p.6] and mWhiteBoard (multicast 
WhiteBoard) [Pames 97a p.6 (was mWB)] to discuss issues with other on-line students without interrupting the 
lecture or to part in lecture exercises. Interaction can also take the form of voting on different issues by using 
mVote (multicast Vote) [Pames 97a p6]. This gives on-line students possibilities that do not exist in a classic 
classroom environment. 

Furthermore, the teacher can include a playback of a recorded session into the live lecture, which enable 
reviewing and debating of related recorded material. 

2.3 Asynchronous playback 

The lectures are recorded using the mVCR application, and then edited using mEdit [Norrg&rd 98]. Indexes, 
i.e. named temporal points in the lecture, can be added by the technician while the lecture is taking place or by 
the teacher afterwards. A teacher can also add comments, modify the flow of events, remove sequences such as a 
long pauses and insert previously recorded multimedia content. Adding slides, a famous speech by a Nobel prize 
winner or a clip from a previous lecture can easily add a lot of content value to a lecture. 

The WWW interface to the mMoD server allows reviewing recorded lectures by starting playback sessions. 
Participants can join in on playbacks currently being played by others or start their own playback. Interaction 
between the participant and the mMoD server is done via a mVCR control -applet started from the mMoD WWW 
page. mVCR provides basic VCR-like functions and access to the indexes of the lecture. It enables the student to 
quickly jump to the desired part of the lecture without having to fast-forward through the lecture. During 
playback, the participants can view all multimedia sources and events that occurred in the original lecture. The 
flow of the slides, mChat, mWhiteBoard and mVote events are all preserved and played back. 

2.4 Virtual meetings 

Aside from lectures, using this environment in combination with newsgroups and traditional mailing list can 
create a 'virtual student community' in which students can help each other for labs and participate in course 
related discussions. Students are able to cooperate and interact with each other using the previously mentioned 
suite of tools. Helping other students with labs, course questions or simply sharing experiences add a 
collaboration dimension to distance based courses. Creating such a community, as described in [Lai 95], can be 
very useful for both students and a teacher's workload. 

It is also possible to have a 'virtual teachers room' session using audio and video tools. This works like a 
virtual corridor, where the students enter and ask questions or discuss course-related issues. For distant students 
it is naturally very important to have a continuous contact with the teachers. 

By combining the possibilities offered by available networks, the collection of portable tools written in Java, 
the accessibility and ease of use of the WWW and the benefits of IP-multicast, we have been able to make these 
scenarios part of our everyday, real-life teaching experiences. We would like to stress that this is a working 
system in real use. 


3. The mWeb Application 

The mWeb application is a tool for real-time distributed presentations in HTML. The application includes 
functionality for distribution of HTML-pages, including in-line data and embedded objects, pre-caching of files 
to be used within a session, on-demand fetching of files and synchronization between browsers. mWeb uses the 
mDesk framework for distribution and control [Pames 97a p.23, Pames 97d]. 

The mWeb application acts as a gateway between a WWW browser and the MBone, mediating distribution 
of HTML-pages and 'display-messages’. The application can also run in a lightweight mode, where only the 
URLs to be displayed are multicasted. This is useful in smaller groups as the delay becomes shorter and the 
network usage does not significantly change. 

Normally URLs are collected dynamically during a presentation using the special mWeb WWW-proxy that 
sends information about the requested pages to the mWeb application. This is achieved by directing the browser 
to request all pages through the proxy, instead of fetching them directly. Offcourse a list of URLs can be 
prepared before a presentation as well. 

The first problem related to distribution of the WWW based presentation material is how to distribute WWW 
pages efficiently to a large group of listeners. The solution is that the presenters m Web instance fetches the page 
content to be presented from the server and then distributes it to the listeners. The distribution is done using the 
/TMP (Tunable Multicast Platform) [Pames 97a p.26], which allows for reliable transfers using the inherently 
unreliable IP-multicast. 

When a presentation is distributed over the MBone and a WWW browser is used for presenting the slides, 
there is a need for synchronization between the involved WWW browsers (that all involved browsers display the 
same page). This is solved by sending a display-message to all members of the group using the CB (mDesk 
Control Bus) [Pames 97a p.26]. 

During the session, all pages that are received are collected in a list. The listener has the choice of either 
automatically displaying a new page or manually clicking on the list entry to display a new page. If a listener 
wants to go back and view an already displayed page, s/he can select the page of interest in the list of received 
pages and that page will be displayed locally. The user can also instruct the local mWeb client to send a display- 
message to all other listeners including the presenter. This is useful if the listener wants to comment or ask a 
question related to a page that is not currently displayed. 

4. Discussion 

We have noticed that using mStar to teach about it's own underlying technology was a very good idea. By 
doing this, students that take the course are often more technology oriented, and are less hesitant towards using a 
microphone and video camera to interact. The under-graduate courses at the university are becoming very 
popular, perhaps because they teach technology using technology. 

The statistics from our mMOD server logs show that many students prefer to watch lectures during evenings, 
or even late at night. Offering the opportunity to study asynchronously has its price; the lectures are becoming 
less frequently attended. This might not be entirely negative, as courses today are growing in size with 
sometimes more than 120 students, and it can be very useful for students having overloaded daytime schedules. 

Using the playback facilities offers another clear advantage: it enables students to take pauses, to either read 
additionally related information or to consult the course literature. Unfortunately, these students can not be part 
of the spontaneous discussions during lectures. Having multiple participants active in the playback environment 
might remedy this to an extent, but this is clearly an area to be improved. 

The multiple gathering of students in groups to listen to the playback of a lecture is also a remedy to the latter 
problem. This social behavior might come from a need of discussing the material similar to discussions that take 
place in an ordinary lecture. 

We have noticed that other social protocols have been established when using the environment for 
presentations and education. Foremost are the sub-discussions that take place using the mChat and m WhiteBoard 
tools, where a set of the participants either discuss the presenters material or something completely uncorrelated. 
This kind of discussions and sharing of information enhances the learning experience, since attending a lecture 
physically normally disallows side conversation in the audience. 

By encouraging the use of different means of communicating electronically, such as email or WWW-based 

discussion media, we have found that students tend to help each other. This form of social clustering, is most 
interesting. Not all choose to take part, but since a large number does, it lessens the traditional burden of a 
teacher. Students with additional knowledge have also the opportunity to share it with the rest of the class and 
the teacher. The fact that students are able to share this knowledge with the group is an enormous advantage to 
more traditional teaching, where students seems to rarely form groups with more than five members. 

An additional observation made using the mStar environment for lectures is that lectures tend to become 
more static than classical (i.e. non electronic) lectures. Experienced teachers are most often those who can 
improvise and dynamically alter the course of a lecture. These teachers usually do not need to prepare overhead 
material, as their lectures often take the shape of a normal conversation. With mStar, teachers are easily 'caught* 
in the flow of their pre-made electronic material. It is therefore very important to still allow the teacher to 
improvise, perhaps by adding links to in-depth material from the original presentations and making use of an 
electronic whiteboard or a sketchboard. 

Furthermore, a technician is needed to achieve the best transmission quality for the lectures. The technician 
controls audio levels, camera focus and positions, recording management and lighting in the lecture hall. This 
means that two persons are needed to conduct a distributed lecture. This extra requirement in human resources 
should be justified by the fact that no teachers are needed at the 'distance-based' locations. The use of movement- 
tracking cameras and automatic audio level control equipment, can remove the need for the technician. 

Traditional distance education methods usually take the shape of TV broadcasts. In comparison with the 
mStar environment, networked distance education offers more than the ordinary TV broadcasts. Although mStar 
could certainly be used in a more 'TV-like' environment, such as a one-to-many broadcast media, there are some 
fundamental differences: 

• Setting up TV sessions can create many distribution-related headaches. Broadcasting regulations and 
equipment availability are two major potential pitfalls. With the multicast technology used in mStar, 
sessions are more lightweight and are easier to create. Multicast sessions also allow for more channels 
than the two available educational TV broadcast channels in Sweden. 

• TV offers no interactivity at all, while net-based education can offer several means for interactivity. 

Finally, training teachers at remote secondary schools has had a very positive effect. These teachers tend to 
spread the gained knowledge about this technology and information technology in general, creating a very nice 
momentum for mStar and for the teachers in general. The fear that knowledge about information technology is 
decaying at secondary schools in Sweden can therefore clearly be met. For sparsely populated areas like the 
county of Norrbotten, networked distributed education might be the future. If the Internet is the next industrial 
revolution, then netbased learning may be the next educational revolution. 

5. Summary and Conclusions 

This paper describes a novel multimedia environment for distributed education offering many different usage 
scenarios. The mStar environment consists of a tool suite for preparation of presentations, distributed 
presentations, playback of recorded and edited multimedia content, and synchronous virtual meetings. These 
tools and scenarios, tightly integrate the WWW in a close relationship with IP-multicast technologies. 

The variety of usage experiences and the successful county-wide deployment clearly demonstrates that mStar 
is indeed scalable in more ways than one. From small informal presentations to complete university courses, we 
have shown the strength of this novel education environment. 

We have argued this from a variety of perspectives, all showing that this environment offers extended 
support for interactivity, better help through the use of a 'virtual student community', as well as on-line 
availability of all course media. The goal is to create an educational environment that can be qualified as better- 
than-being-there, bringing everyday situations such as interacting, learning and collaboration to the Internet. 

6. Future work 

The most important future enhancement of the mStar environment is in the field of usability, where a study 
could be done by having two user groups, one that follows a course remotely and one that follows it locally, and 
then compare the results. In addition, better mMoD logs might reveal interesting statistics about usage. These 
results should help in making mStar easier to use. Using mStar should not be harder than just clicking on a link, 
especially for primary and secondary school students. 



The users of the mStar environment have identified a need for further development, in order to better support 
distributed education. The most frequently requested functions are: 

• An enhanced SlideBurster with support for outline editing, HTML templates using Cascading 
StyleSheets and incorporation of the new W3C standard SMIL. 

• An integrated tool for playback of audio, video and HTML (replacing VIC, mAudio and mWeb). This 
component should be implemented with the Java Media Framework to achieve portability. 

• Support for a movement-tracking camera together with automatic adjustment of audio volume levels, 
which will lessen the need for a technician. 

• Privacy through encryption of the media, for sensitive or confidential information. This is also needed 
for ’pay per lecture’ education. 

• One-to-one audio/video communication within a larger session, for side conversations. 

• General application sharing across platforms. 

• Remote pointers for pointing certain paragraphs or positions in HTML slides. 

Another area of future work is enhancement and expansion of the virtual student community, since 
spontaneous discussions among students and teachers are vital, even if asynchronous. Adding a shared 
information space like a WWW based bulletin-board will be investigated, perhaps by using the education 
framework presented by Lai et al [Lai 95]. 

7. References 

[Perron 94] Perron, D. (1994). Learning on the WWW: A Case Study. Second International WWW conference 
(WWW2), 1994, Chicago, USA. 

[Goldberg 95] Goldberg, M., & Salari, S., & Swoboda, P. (1995). World Wide Web - Course Tool: An 
Environment for Building WWW-Based courses. Fifth International WWW conference ( WWW5 ), 1995, Paris, 

[Ibrahim 95]Ibrahim, B., & Franklin, S. (1995). Advanced Educational Uses of the World-Wide Web. 

Third International WWW conference (WWW3), 1995, Darmstadt, Germany. 

[Lai 95] Lai, M., & Chen, B., &Yuan, S. (1995). Toward A New Educational Environment. 

Fourth International WWW conference (WWW4), 1995, Boston, USA. 

[Pames 97a] Pames, P. (1997). The mStar Environment: Scalable Distributed Teamwork using IP Multicast. 
Licentiate Thesis, Lulea University of Technology, 1997. 

[Pames 97b] Pames, P., & Synnes, K., &Schefstrom, D. (1997). The CDT mStar environment: Scalable 
Distributed Teamwork in action. International Conference on Supporting Group Work (Group'97), 1997, 
Phoenix, Arizona, USA, November 16-19. 

[Deerig 91] Deering, S.E. (1991). Multicast Routing in a Datagram Internetwork, PhD Thesis, Stanford 
University , December 1991. 

[Jacobson 95] Jacobson, V., & McCanne, S. (1995). vie: A Flexible Framework for Packet Video. In 
proceedings of the ACM Multimedia , 1995. 

[Norrgard 98] Norrg&rd, J. (1998). mEdit : An editing tool for thr mMOD system. Master Thesis, Lulea 
University of Technology, April 1998. 

[Pames 97c] Pames, P., & Mattsson, M., & Synnes, K., &Schefstrdm, D. (1997). The mWeb Presentation 
Framework. Sixth International World Wide Web Conference (WWW6), 1997, Santa Clara, California, USA, 
April 7-11. 679-688. Also appeared in the WWW 6 special issue of Computer Networks and ISDN Systems, 
September 1997. 

[Pames 97d] Pames, P., & Mattsson, M., & Synnes, K., &Schefstrom, D. (1997). The WebDesk framework. 
Seventh Annual Conference of the Internet Society (INET’97), 1997, Kuala Lumpur, Malaysia. 


Thanks should go to Ulrika Wiss and Johhny Wid£n at CDT, for interesting comments and nice 
encouragement. We would also like to thank the project Education Direct, which is supported by the Swedish 
Foundation for Knowledge and Competence Development. Support was also provided by the Centre for 
Distance-spanning Technology, CDT, and it's members. 

U.S. Department of Education 

Office of Educational Research and Improvement (OERI) 
National Library of Education (NLEJ 
Educational Resources Information Center (ERIC) 



This document is covered by a signed “Reproduction Release 
(Blanket) form (on file within the ERIC system), encompassing all 
or classes of documents from its source organization and, therefore, 
does not require a “Specific Document” Release form. 

This document is Federally-funded, or carries its own permission to 
reproduce, or is otherwise in the public domain and, therefore, may 
be reproduced by ERIC without a signed Reproduction Release form 
(either “Specific Document” or “Blanket”). 

EFF-089 (9/97)