William Tan, Distance Education Centre, University of Southern Queensland, Toowoomba, QLD 4350, Australia. Phone: +61 76 312 877 Fax: +61 76 312 868 Email: TanW@usq.edu.au
Lynne Kezunovic, Faculty of Engineering and Applied Science, Griffith University-Gold Coast, PMB 50 Gold Coast Mail Centre, QLD 4217, Australia. Phone: +61 755 763 143 Fax: +61 755 948 679
Interactive multimedia (IMM) on the World Wide Web (WWW) is a new phenomenon that has only emerged quite recently. While it is a sophisticated medium with the potential to be highly appropriate for tertiary distance education, major improvements in various aspects of digital audio and video technologies are now required to make interactive multimedia truly acceptable to large numbers of educators and distance learners.
This paper consists of two main parts. In the first part we examine the design and implementation of an interactive multimedia application on the Web. The discussion covers the process of selecting a suitable Web server, its installation and administration. It also deals with the design and implementation of interactive multimedia courseware, and materials for electronic journals, under the new Windows NT operating environment. In addition, we examine important aspects of instructional design of electronic material for the Web.
In the second part of the paper, we explore the implications of the emerging technologies in this area for the tertiary education sector. These technologies will both influence, and be moulded by, new directions in education policy and practice. As the pace of technological innovation accelerates universities will be under increasing pressures to utilise technically-enhanced education tools to capture and hold their shares of the tertiary market. This will no doubt prompt much rethinking about the optimal application of new technologies as well as about the inner life of universities.
The choice of a Web server in this paper is limited to the cost effective, Intel based Pentium PC server running under Windows NT Advance File Server v3.5.1 operating platform with native multi-threading support. As an example, the Intel P90 NT Web server is quite economical and has been shown to be capable of handling HTML (HyperText Markup Language) documents with an average size of 5000 bytes (40,000 bits) at an average of 30 requests per second [HREF1], or 2, 592,000 per day.
The bandwidth needed for a Web server to handle, say, an average of 50,000 connections per day and 40,000 bits per HTML document, can be estimated, using the following formula :
(average connections/day) / (24x60x60 seconds) x (average HTML document size) = 50,000 / 86400 x 40Kb = 23.25 Kb per second.
Note, however, that the average size of a multimedia document would be at least 10 times that of a text-based document. Hence, the bandwidth requirement will be proportionately increased. The capacity of the academic Internet may be saturated and a higher Internet bandwidth will be required in the future if more multimedia applications are to be implemented for the Web.
The total number of transactions per second and the total data rate are important factors to consider in determining whether the capacity of a Web server is adequate to provide the intended services. The number of simultaneous connections which a Web server can handle will depend mainly on the average size of HTML document being delivered, the line speeds of the Web server and that of the clients. The number of concurrent tasks to run under an NT server system should be adjusted so as not to overload the system.
In selecting HTTP (HyperText Transfer Protocol) server software, features such as security, logging mechanism, protocol support, and server-side includes must be taken into consideration. Other aspects which are important include vendor's technical support, maintenance and upgrade services, as well as whether the product is constantly being improved and developed to cater for new multimedia requirements and advances.
The server-side includes is the common name for server-parsed HTML files. Server-side includes can include files as well as the values for environment variables such as dates and authors' names in a HTML file. The Web server scans the HTML file with the extension .HTP (Hypertext for server parsing) for special commands and will replace these commands with appropriate data.
The feature of virtual servers -- for a single Web server with more than one Internet protocol (IP) addresses -- allows different Web home pages for different IP addresses, each with its own domain name. However, the Windows NT v3.5 system allows only 5 IP addresses, whereas the Windows NT v3.5.1 system can have up to 100 IP addresses. The first 5 IP addresses can be entered from the Windows NT control panel, and additional IP addresses must be entered using the Windows NT Registry Editor. Each virtual server has its own environment and configuration; that is, each virtual server can permit its own directory browsing, or authenticate its own client requests.
A recent Web servers survey [HREF2] reports that the four most popular Windows based NT HTTP servers are :- (a) Netscape-Communications [HREF4]; (b) Netscape-Commerce [HREF4]; (c) Website [HREF5]; and (d) Purveyor [HREF6]. The Netscape Commerce server is the most secure server with built-in proprietary Netscape Security Sockets Layer (SSL) protocol and with public-key encryption and authentication. The popularity of Web servers will change with time as better and more advanced software becomes available.
To install NT Web servers typically the detailed configuration information must be provided. The server configuration will usually need information such as the hostname, path to the home directory, files for access and error logging, and port for audio connection. The document configuration will need information such as the path to home page directory and the file name of the home page. The administrative configuration must specify the administrator name, the host name and port number for administrative access. The server administrator must have the same file access and security privileges as that for the Windows NT file server administrator.
If a security Web server is selected, then security must be enabled by generating a private and public key pair. They must then be sent to a public key certification authority requesting an X.509 digitally signed certificate before compiling and implementing them into the security Web server. The public key is used to exchange the session keys, to encrypt data and to verify the authenticity of a digital signature. The private key is used to decrypt session keys that were encrypted using the matching public key. The ciphers used for a security server ranges from the more secure RC4/RC2 ciphers with 128 bit encryption to a commonly used RC4/RC2 ciphers with 40 bit encryption. The private key and administrator password must be protected for secure server administration and operation.
If the server log analysis by sources of incoming access is required (for example, from a newsgroup, a Web advertisement or a home page uniform resource locator URL) then it may be necessary to implement a few identical but independent home pages so that the statistics of incoming access trends and their correlation can be collected.
If the Web server is to perform both HTTP and FTP (file transfer protocol) functions and separate access logs are required, then all URL's that specify HTTP as the access method should be relative within the HTTP directory structure, and URL's that linked to DOS zip files, PostScript or Adobe Portable File Format files on the FTP archive should be absolute URL's using the file access method.
Most of the components of interactive multimedia presentations are just digital representations of familiar media types integrated and displayed on the screen. The ability of the WWW to represent interactive objects in the HTML document and to view them on the Web, offers opportunities for educators and multimedia authors to design interactive multimedia content for their courseware, which can be delivered on the Web as part of a total system of distance education materials.
The use of Web multimedia authoring tools, which allow Web authors to create multimedia applications efficiently for delivery on the Internet, will facilitate the development of Internet courseware. These authoring tools can generally be classified into two categories :- (1) the scripting-based tools such as Macromedia Shockwave for viewing Macromedia Director animations; and (2) the visual authoring tools such as IconAuthor v7 with Internet object oriented authoring capability.
The Director is a timeline and scripting-based authoring tool typically used to create animations for CD-ROM titles which will require high bandwidth and continuous delivery of data. It should be noted that the speed of a quad speed CD-ROM is about 100 times that of a dial-up speed of a 28.8 kbps modem so that for most users, the dial up Internet will not have a high enough bandwidth to run the Director application effectively.
IconAuthor is an event-driven object-oriented tool with unique separation of programming structure and content. All media input are stored in their native file format which can be located at different remote sites external from the multimedia application. In the IconAuthor v7 interactive multimedia application, an HTML object can display HTML documents created from any HTML editors, and a table object can support for viewing multiple database records simultaneously. The interactive multimedia courseware developed can contain multimedia objects such as buttons, pull-down and pop-up menus, special effects and animation clips, audio and video clips and on-line forms to capture user feedback and responses. It should be noted that IconAuthor is not an HTML editor and its free runtime player has to be launched as a helper application in a windows-based browser.
Most of the interactive multimedia Web courseware which has been developed so far can be classified into three categories. The first category includes the `store and forward' multimedia applications such as the on-line Web programming courses which provide storage, retrieval, easy navigation aids and index searching of a variety of course materials and multimedia data. It also includes remote information kiosks with multimedia information about a particular subject or place of interest.
The second category covers real-time interactive multimedia applications such as the real-time desktop video conferencing with live voice and real-time video.
The third category comprises the integrated applications with both store-forward and real-time multimedia components, such as the virtual distance education classroom which provides interactive training with multimedia courseware and an on-line instructor to answer queries and to give instantaneous real-time interaction and feedback.
The ability of the WWW to present multiple views and multiple entry points into the same logical set of documents, enables the electronic publishers to offer their electronic journals on-line and make them easy for users to navigate. The same set of journal articles can be designed so that users are able to navigate these documents by different views such as by document subject, document type, product type, alphabetical document titles, chronological order and by random word search within the constraints of the set of document-type categories.
The ability of the enhanced windows-based browsers to include interactive multimedia materials and to allow Web users to interact and respond to any of the on-line product information within a Web page, has made the Web viable as a powerful media for electronic publishing and as a mass distribution channel of information for millions of users on the Web. Some innovative electronic journals allow small advertisement buttons at the bottom of featured articles. By clicking on one of these buttons which are non-intrusive but available to those that want them, the user can be linked to a product's or an information provider's home-page.
As more electronic information and multimedia materials are available from the Web, the problems of copyright and content ownership of intellectual property become important. It is vital for the information provider to make sure that they do not infringe on any international copyright laws. They must either, in the case of electronic textual materials, declare and identify the ownership, copyright, and reproduction rights; or, in the case of electronic graphical and multimedia materials, obtain permission rights for global, electronic distribution before making them available on the Web.
There exists many guidelines for the design of a Web document and its hyperlinks. These guidelines are available on the Web or in print [HREF3]. Some important guidelines are listed below :-
Instructional design for IMM Web application involves not only Web document design guidelines, but also cognitive, structured and communication design principles. Depending on the nature of the Web application, an integrated design principle incorporating some or all of the above principles may be necessary.
A spatial hypertext design methodology as proposed by Marshall (1994) should be used for interactive multimedia Web applications that involve the collection, comprehension, and interpretation of diverse materials; and those whose domain structure is not well defined and can be changed by a task. The spatial hypertext design can not only provide users and authors with visualisation of existing structures but also allow human perception abilities in hypertext navigation to experiment and manipulate existing structure.
By contrast, a formal Relationship Management Methodology (RMM) as proposed by and Batasubramanian, Isakawitz and Stohr (Batasubramanian, 1994) can be used to formalise and automate the design process for interactive multimedia Web applications which are highly structured and have high information volatility that requires frequent updates -- such as on-line course brochures and interactive multimedia applications with large data base of objects and with definable relationships between classes of objects. Basically, the RMM uses traditional data model approach with six access primitives to define navigational linkages required by the Web application. It focuses on entity relationship and navigation to design the Web access mechanism. The design step uses a set of conversion rules to transform the design into Web objects in a target platform. For example, an HTML form can be used to implement an index of accesses. The next step in the user-interface design involves the design of button layouts, appearance of HTML page nodes and indices, and location of navigational aids. The runtime behaviour design step is then performed to decide on link traversal, history and navigational mechanism. The final design step consists of construction of a working prototype and testing of all navigational paths.
Originally, distance education was typically seen as a mode of delivery of education for people who, for reasons such as location, physical disability, family responsibility or the demands of employment, find it difficult to attend regular on-campus classes (Dekkers,1990). However, the rapidly growing capabilities of electronic technologies mean that the boundaries of on-campus and distance education have become blurred (Rossman, 1992). The emphasis is now on flexible learning, which essentially could be defined as being free from geographical, time or participation restraints. Although conferencing and collaborative projects allow group participation, it is neither mandatory or present in all forms of flexible learning. Furthermore, classes may be at a distant location, or on-campus, or both; and typically involve computer-based courseware as well as traditional modes of delivery. Modes of flexible learning now include computer mediated instruction, virtual on-line universities, correspondence courses, teleconferencing and off-campus instruction by an instructor either at a distance learning centre or at some other location.
The delivery of flexible learning has evolved in accordance with the availability of new technology. This evolution has been described by several authors in terms of four generations [HREF7]. The traditional form of correspondence or broadcast courses was the main means of education for the Australian outback (remote homesteads, isolated farming and mining communities) and is described as first generation. This presented few opportunities for interaction. Secondly, media such as video allowed a closer approximation to the classroom experience. Then, technology such as computer conferencing, electronic mail and voice mail supported further communication between tutors and peers and is described as “third generation”. The fourth generation will emerge around the late 1990s will support direct access to large databases, hypermedia stacks, and dial-up access to video and text material. Students will be in control of the time, place and pace of study, and will have direct access to a wide knowledge base and be able to communicate dynamically with faculty and peers [HREF7]. Although the Web is still an immature technology, it already possesses these fourth generation functionalities with potential for further advancement.
Flexible learning can be much more cost-effective than conventional modes of education if the support infrastructure, such as courseware, equipment, and databases, is already in place. This gives rise to the promise that universities may be able to meet, within reasonable budget parameters, the demand for additional facilities and resources from the rapidly escalating student population, and the concomitant rise in staff numbers.
A Commissioned Report was produced by the National Board of Employment, Education and Training in November 1992. It points out that government policy has been amended to permit capital funds to be spent on technology and course development which extends distance education and reduces the need for on-campus buildings. Government expenditure on tertiary buildings for the period 1991-1994 was $1016.398 million. The demand for new buildings and car parks has been exacerbated by the ever-increasing student population in universities.
The declining ratio of academics to students also places increasing demands upon academic staff. Both for economic and pedagogical reasons, students are being encouraged to become more independent learners. Flexible learning, especially via communications technologies like the Web, is an alternative way of distributing courses to a large number of students.
The Web has many capabilities useful to flexible learning. It is relatively easy to use, inexpensive to install and to maintain. Client, server and tool software is readily available as freeware. If students are to become inquiring independent learners, then they need ready access to current information resources. Yet it is simply too costly to provide such resources at every physical location. By contrast, the Web can provide access to databases all over the world. It also allows a broad spectrum of world-class expertise to be available to students, even those in remote or sparsely populated areas.
Advantages other than those of a financial nature exist. The Web was originally conceived for the purpose of collaborative research and continues to be useful in this regard. Collaborative projects assist students in developing their skills in communicating information and ideas to others and ability to work in a team. A current example of a collaborative project is a physics program delivered to a small number of Honours students at the University of Melbourne. The primary reason for transposing this course to the Web was to harness its capability as a vehicle for collaborative learning and mentorship, and to support those students who were experiencing difficulties [HREF8 and HREF9].
Diana Laurillard of the Open University, United Kingdom, supports the view that simulation in computer-based courseware can promote sound understanding of a subject area (Alexander, 1995). The University of Melbourne has used simulation in a course called “Population Dynamics Project”. The principal advantage of delivering this on the Web, is that it allowed visually-enriching photos of various animals and their habitats to be viewed by students in their own time. The simulator also allows students to test `what if' scenarios by inputting various parameters such as age of animal. Newsgroups were established to promote unstructured group collaboration. The Web's ability to view news provides a consistent interface for students. Students can also ask questions on forms which were responded to by tutors (Riddle et al, 1995).
Electronic courses offered in Satellite Learning (Spring 1991) magazine fall into a number of broad groups (Rossman, 1992):
It is interesting to note that courseware on the Web in 1996 consists of a similar mix of computer science, engineering, medicine, teacher training and business.
Practical considerations in producing courseware on the Web have resulted in an accumulation of knowledge and expertise in HTML page design, in handling the necessary hardware/software requirements on different computing platforms, and in the management and updating of the content in the Web Server [HREF10].
Security: It is generally recognised that Web client and server security is weak. The three major types of security are:
At present, user authentication, together with encryption resident on the host server can be implemented. This is at the security level which should be adequate for the delivery of courseware. Research is being carried out to include encryption in the HTTP header to ensure that data is secure when it is in transit over the Internet. This will provide the higher levels of security required for highly confidential material.
Loss of Human Contact: Some critics are concerned about the reduction in human contact with instructors. It has been argued, however, that even though students and instructors need to stay in contact through email or phone, they do not require the same kind of socialising that goes on in classrooms. In practise the major source of frustration has tended to be a faulty computer delivery system. Thus successful on-line courses require regular technological assistance and support for the instructor. If this is provided then student satisfaction can be as high as those on-campus (Rossman, 1992).
Academic Staff: Many faculty members may not feel empowered by computer technology. In fact, the reverse may often be the case. It is hard for some to envisage how it could be integrated into their courses. Most importantly, they may be inundated with their current duties and may feel that instructional innovation is not adequately rewarded. What is required may be a change in the tenure system to award points for teaching innovation toward tenure (Santaro, 1991).
A strategic plan to train staff in new techniques may be desirable. Lecturers and tutors will still need to take on the role of adviser, helping students to get started, manage their time and cope with self-doubt (Rowntree, 1992). Workshops could be introduced to cover course writing and editing, instructional design and course development and the use of the computer as a management tool in distance education.
The Role of Technical Staff: An outward orientation should be encouraged among technical support personnel. Their assistance will be needed to update material on the server so that it is current and adequate, change passwords, and assist in the courseware development and its ongoing support. Successful online classroom requires regular technical assistance and support for the instructor.
Management of Learning: Hypermedia capabilities are a powerful and unique feature of the Web. Nevertheless, there is a danger of some learners becoming `lost in hyperspace' without any clear signposts as to where they are going. Research into the interaction of hypermedia and different learning styles is continuing to grow as a new area of research.
Peter and Trudy Johnson-Lenz, after a decade of creating online courseware, believe that “connecting people without clear purposes, processes and norms to guide their interactions results in scattered and sporadic activity.” What seems to be missing is “support for different learning styles, self-directed learning, education for the whole person and learning how to learn” (Rossman, p.142). A new research area concerns the effect which pure hypertext has on different learners. For instance, field-dependent learners prefer structure and concrete examples in the presentation of material. Conversely, field-independent learners rely on internal gravitational cues and prefer a discovery approach. Accordingly, it seems that field-independent learners will excel in navigating hypertext over field-dependent learners.
A major feature of the World Wide Web is its hypertext capabilities. Hypertext links can be created from within documents and between documents. Nelson Ted (inventor of hypertext and hypermedia) intended to “enhance and nurture our minds and capabilities”, taking us far beyond former levels of literacy to new levels of understanding and intelligence (Rossman, p.141). Many writers have supported hypertext because it matches the semantic network of human memory. On the other hand, severe criticism has also been levelled at pure hypertexts, because of their lack of pedagogical structure. This results in some learners getting `lost in hyperspace'.
The question has been raised as to whether some learners can easily adjust to a hypertext map which is imposed upon them by the author of the hypertext (Alexander, 1995). Undoubtedly, learners who are not very computer literate will experience difficulty in navigating through pure hypertext without some supportive structure. Two types of supportive systems are Adaptive Hypermedia Systems and the Three Phases Navigational Model.
Adaptive Hypermedia Systems use Intelligent Tutoring System (ITS) technology to channel the learner according to their ability through hypermedia. The presentation of a node or the links departing from the node are adapted in accordance with a user model. The computation for this link-adaptation is derived from artificial intelligence techniques (Linard and Zeiliger, 1995).
The Three Phases Navigational Model has been applied by Linard and Zeiliger to courseware for psychology students. The Orientation Phase covers the explanation of the function of main buttons and main tasks involved. In the Initiation Phase an explanation of the content of the course is provided. Finally, in the Reflexion Phase the user constructs a conceptual map of the subject domain. This is achieved using simulation and comparing it with a test module.
The Web is a cost-effective, alternative delivery vehicle which can address many of the issues in flexible learning. Its hypermedia capabilities, together with global database access, collaborative online projects and ability to deliver courseware across distances and at different times make it a powerful tool in this field. These capabilities can assist students to develop the qualities desired by employers and society. The two key areas critical to successful implementation of flexible learning on the Web are suitable technical infrastructure and a thoughtful approach to the use of new technologies.
S Alexander (1995) “Teaching and Learning on the World Wide Web”, UTS, mimeo.
P Balasubramanian, T Isakowitz and EA Stohr (1994) “Designing Hypermedia Applications” in R H Sprague and B Shriver (eds) (1994) Proceedings of the 27th Hawaii International Conference on Information Systems (HICSS), IEEE Computer Society Press, Maui, HI, pp 354-365.
J Dekkers (1990) “Education for All: The Tyranny of Distance Overcome?”. The Inaugural Lecture. University College of Central Queensland, Rockhampton.
M Linard and R Zeiliger (1995) “Designing a Navigational Support for an Educational Software”. CNRS-IRPEACS, Ecully, France, mimeo.
CC Marshall, FM III Shipman and JH Coombs (1994) “VIKI : Spatial Hypertext Supporting Emergent Structure”. Proceedings of the European Conference on Hypermedia Technologies (Sept. 18-23, Edinburgh, Scotland). ACM, New York, 1994, pp 13-23.
National Board of Employment, Education and Training (1992) “Changing Patterns of Teaching and Learning: The Use and Potential of Distance Education Methods in Australian Higher Education”. Commissioned Report No.19. Australian Government Publishing Service, Canberra.
P Rossman (1992) The Emerging Worldwide Electronic University: Information Age Global Higher Education. Greenwood Press, Westport.
D Rowntree (1992) Exploring Open and Distance Learning. Kogan Page, London.
GM Santaro (1991) “Computer Empowerment and the Ten Thousand Things” in Distance Education Symposium: Selected Papers, Part 2. Papers Presented at the American Symposium on Research in Distance Education, University Park, Pennsylvania.
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