Appears in Proceedings of the First Workshop in Multimedia Signal Processing, editors Y. Wang, A.R. Reibman, B.H. Juang, T. Chen, and S.Y. Kung, pp. 507-512, June 1997, Princeton, NJ, IEEE Press.
DISTRIBUTED MULTIMEDIA EDUCATION WITH REAL-TIME FEEDBACK Patricia A. Morreale Advanced Telecommunications Institute Department of Computer Science Stevens Institute of Technology Hoboken, NJ 07030
[email protected] 201/216-8072 Abstract - The delivery of applications with both real-time and non-real-time service expectations, such as multimedia education, using the WWW has led to a new model for service provisioning. The profile of a distance learning session, including video-ondemand, is unlike any other service delivered over the WWW or a dedicated intranet. After developing several WWW-based multimedia distribution systems for distance learning. a profile and service expectation has been developed. By including real-time feedback to the students and administrators, information about the effectiveness of the education being delivered can be made. A pre-fetch or reservation strategy, coupled with historical information about student behavior can significantly improve information delivery to the desktop. Presentation of this model, a discussion of the design, and analysis of the results found in actual use will be provided.
INTRODUCTION Several issues remain constant regarding the delivery of education on demand. • accuracy and appropriateness of education delivered • timeliness of information • integration of information delivery with assessment The system outlined here addresses the assurance of accurate and appropriate education , with real-time feedback, including assessment. The model described has been implemented. There are several forms of distance learning. Among the most popular are video conferencing, computer-based training and networked multimedia Each of these has advantages and drawbacks, which are outlined here.
Video conferencing Video conferencing, whether delivered to a desktop or to a room, is widely used by corporation and college campuses [1]. An obvious advantage is the opportunity it
offers for the off-site participation of individuals who would otherwise be unable to participate in the learning opportunity. Drawbacks include the real-time attendance constraint. In order to receive the benefits of video conferencing, a student must be present at the time of the video conference. Otherwise, features such as question and answer sessions and interactive problem solving cannot be taken advantage of. The non-real-time solution to this process is to provide video tapes of the video conference, which the student then view at leisure. This is far from the original goal of participatory educational delivery. This concept is "second-class", not the real thing. It is useful in the event that physical attendance in the traditional lecture classroom is not possible.
Computer-based Training Computer-based training, such as that received from training software or CD-ROM systems is also widely used. This approach presents "static" or packaged lessons which students can work their way through. Updates to the lessons require the manufacture and distribution of new training software modules or CD-ROMs. Personal interaction or instruction is unusual. Often used for professional training, this impact of this approach is difficult to assess. The lack of interactivity and the reliance on canned and pre-programmed responses corresponds to the lack of student enthusiasm for this approach.
Networked multimedia delivery systems Networked multimedia delivery systems provide a "dynamic" environment for the delivery of educational material, such as courseware [2]. Curriculum updates or changes can be made instantly and delivered to students promptly. Supporting and including work in the area of hypermedia courseware, networked multimedia learning permits learning by association, is highly interactive, and can reinforce learning with cues in multiple media. Techniques such as the animation of technical material, iterative problem solving, and real-time feedback of appropriate detail is provided here. Additionally, by using networked delivery, the distributed system can include anticipatory pre-fetch and delivery of materials which have a great probability of being requested next. Potential network bottlenecks can be detected and worked around transparently, without detection by the students.
SERVICE MODEL FOR MULTIMEDIA EDUCATION DELIVERY The service model developed for multimedia education delivery is based on earlier work addressing the design of metropolitan area networks [3]. This earlier effort can be extended to the WWW delivery environment. The asymmetrical traffic pattern identified, such that more information is delivered than user than the user sends to the
network is perfectly replicated in today’s distributed internet service model. Compelling characteristics of applications such as distance education and other applications with a variety of dissimilar service requirements has resulted in the investigation of service delivery which includes real-time and non-real time services. A practical example of this can be found in multimedia education delivery. Unlike many user-oriented systems, the system model used here is focused on the underlying network used for delivery. In designing the system, the goal was to develop an optimal system for distance education delivery which did not place an overwhelming burden on the network delivering the service, while providing a level of service to the users which was appropriate and correct for their learning. The service model which resulted is an early form, which is currently being refined, as a greater understanding of network service assurance in acquired and more complete distance education systems are designed.
DESIGN OF THE MODEL The model developed for multimedia education delivery, and applications of this class of heterogeneous service expectations consists of users connected to the internet, receiving multimedia education delivered using the WWW. The origin of the educational content delivered is a web server, with the requisite content and with a multimedia delivery manager active. Initial development centered on the design of a telecommunications course. This subject was well-known to the developers and there was a demand in the user community for information of this nature. Several lessons, or modules, were developed, with assessment following the lesson. Interactive illustrations were included where appropriate, as the student population which would be receiving this education were experiential learners, those that would “learn by doing”.
Operation of the model Student interaction with the distributed education environment triggers the development of a user space in the multimedia delivery manager (MMDM). Access to the distributed education environment can be controlled by userid and password, if desired. Once the user space is established, the MMDM serves as an observer of the session being conducted by the student. This is necessary so that, if interrupted, an appropriate stopping point can be recorded. Furthermore, the MMDM can compare the student’s interaction with the subject matter and modify delivery of the curriculum, as appropriate. This permits the following features: • scaleable learning modules are implemented. If the student’s interaction with the subject matter requires a modification in the usual sequence of delivery, it can be made transparently, without student invocation. • assessment modules are tailored to the educational material delivered. Based on student responses to educational material delivered,
appropriate review material can be developed for presentation to the student. • anticipatory pre-fetch or reservation of materials which will be needed in the future. As the student proceeds through the educational material, a pattern of behavior emerges, which can be compared with the historical behavior of students • who have previously worked with the material provided • who have previously provided a background profile comparable to that offered by this student As the student proceeds, statistical probabilities of the next activity are computed, taking into account these and many other factors, to develop a highly appropriate and correct learning method for network delivery of the instruction needed by this student. This information, gathered and evaluated in real-time, permits the development and delivery of customized instruction, tailored to the student. In much the same way as a professor tailors a lecture for the students present, their level of participation, and their presented or perceived abilities, so is the distance learning system adjusted through the use of networked delivery methods.
IMPLEMENTATION OF ANTICIPATORY PRE-FETCH STRATEGY Earlier authors [4] have discussed manipulation of the delivery of education based exclusively on the student’s perspective, such as a tutor might adjust the delivery of educational material. The approach used in the design of the system described here promotes the delivery of education suited to the student’s needs, but based on the criteria of the network infrastructure. By designing a distance learning system to work within the network’s service needs, a superior distance learning environment can be established, with greater student satisfaction. One of the challenges in networked delivery of distance learning is determining how to deliver video-on-demand. One of the benefits to the system described here is the ability to determine when specific modules with video elements will be needed. Once determined, the video can be downloaded in the period of time before the student will be working with the module. Or, if the overall network traffic load is such that a video delivery should be scheduled for the evening or early morning, a reservation can be placed, and the video can be delivered in the period of less network traffic. This adjustment of the delivery infrastructure to support both telecommunications and educational needs is incalculable in terms of the potential impact to distributed multimedia educational systems.
DESIGN ASSESSMENT AND RESULTS
An abbreviated version of the resulting telecommunications course, to be delivered via the WWW or corporate intranet environment can be viewed at http://www.ati.stevens-tech.edu/isdn. Once established in the laboratory environment, this course was tested with professionals, responsible for acquiring continuing education for use on the job. The feedback was positive, with networked multimedia educational delivery receiving high praise for the review and reference character of the material, as well as the dynamic content, ease of maintenance, and instant assessment of material delivered. Both students and administrators considered this course offering to be an excellent replacement for traditional lecture presentations or a complement to the lecture presentation. Since the initial course development in telecommunications, this technique has been used for the development of multimedia management case studies. The resulting case study was piloted with several groups of students. Feedback in this instance, varied from “more cases should be like this” to “best project I worked on”. The characteristics of case studies demand group consensus, which was further aided by the networked delivery. The initial prototype presented a very small illustration of this idea. Overall design was innovative for the time, with a variety of alpha elements being included. As the design environment matured, earlier tools were replaced with more mature products. Current implementations of this system model are superior in both performance and network design adaptations to support the educational delivery process. As the process of increasing the community served by this type of instruction increases, additional information will be available regarding overall network impact. The method of observing the type of traffic and analyzing how best to optimize a network for the delivery of heterogeneous traffic, such as that needed by a distance education system, is clear, once presented. Current multimedia system design has not taken advantage of the real-time and non-real-time aspects of networked delivery which are available. Some material, such as responses to user information and assessment results, must be provided immediately. However, other material, such as the overall module template, video or other bandwidth intensive services, can be delivered in a non-real-time environment, and used or discarded as appropriate.
FUTURE INVESTIGATION Further optimization of the service model outlined here may be possible through the use of intermediate hubs or pre-assembly delivery stations. Current delivery has used both intranet and internet solutions, but the concurrent user population is not considered to be more than thirty at any one time. In the event of a wide-spread educational delivery system, such as that which might be needed for national certification or other deadline-driven examination, the expected network load must be calculated in advance, with a plan for staggered delivery devised. In addition, any educational material where certain materials are made available incrementally should also be designed with regard for peak loads. The system designed and in use today is highly rated with regard to • accuracy and appropriateness of the education delivered
• timeliness of information • integration of information delivery with assessment These features have not been highly rated in previous video-conferencing or computer-based training systems. The ability to integrate the distance education environment outlined here with legacy systems and assessment techniques is very important in future design. One of the best features of this approach is the preservation of investment in the distance learning system. Future editions of networked multimedia distance learning systems can easily built from existing systems, without incurring new and additional investments. Future activities include the development of other distance learning course offerings. Depending on the educational approach desired, more complex assessment techniques are being developed. Specifically, incremental learning can be supported thought problem solving with directed feedback, where steps in the problem solution are identified and the student's work at each stage of problem solving is analyzed. An integrated system, the Curriculum and Registration Tool (CRT), is also under development. Using the distance learning system with real-time feedback as a building block, CRT integrates a number of dissimilar components of the learning system and permits remote management and assessment of the efficacy of the distributed learning process. This tool, in conjunction with the distributed learning system described here, permits the delivery of appropriate professional education to the technical workforce of today.
References [1] “Distance Learning with Digital Video”, Fouad A. Tobagi, IEEE Multimedia, Spring 1995, pp. 90-93. [2] “The Design, Development and Evaluation of Hypermedia Courseware for the World Wide Web”, A.D. Marshall and S. Hurley, Multimedia Tools and Applications, Volume 3, Number 1, July 1196, pp. 5-31. [3] “An Analytic Model of a Residential Metropolitan Area Network”, doctoral dissertation, Illinois Institute of Technology, Chicago, IL, 1991. [4] “Curriculum Knowledge Representation and Manipulation in Knowledge-Based Tutoring Systems”, G. Zhou, J.T.-L. Wang, and P. A. Ng, IEEE Transactions on Knowledge and Data Engineering, October 1996, pp. 679-689.
