Development of Digital Networks
Electronic networks for the deliver of distance learning involve transmission media that are ground-based and broadcast linked in ways that are transparent to the user. Ground-based networks include - fiber, coaxial cable, telephone lines, and twisted-pair copper cable. These are seamlessly integrated with undersea cable and fiber, microwave links and satellite to provide a worldwide network that we call the Internet ­ a network of networks that reaches into homes, offices, industries, government, and learning organizations. The use of these networks has been popularized since 1993 by Graphic User Interfaces (GUIs) that enable people with little or no training to access the vast resources of the Internet.

The Internet is a chameleon that is adaptable to a great variety of needs and interests, be they commercial, academic or personal. Email simplifies written communication, while chat rooms and forums permit interactive communication in real time (synchronous) and at different times (asynchronous). Surfing the net enables us to access vast information resources, access libraries and government documents, track news and weather worldwide, explore and visit over 100 countries, go shopping, of find a new job. New communication forms have developed such as listservs and threaded discussions to facilitate dialog and development of new ideas.

As with many new media, the Internet began with text communication. Addition of graphics and audio was facilitated by the Mosaic Graphic User Interface, and from this came Netscape, AOL, Microsoft Explorer, and a host of others. Then came audio, photographic images, and QuickTime video. The video files were too large to deliver and playback in real time, so video excerpts were short and small in size. The limitation was in bandwidth of telephone lines and slow modem speeds. Over time, many of these constraints have been overcome.

Technology has upgraded compression algorithms for video, increased modem speeds, and optimized results using Plain Old Telephone Service (POTS). Internet Service Providers have setup local nodes so that Internet access was available for the cost of a local telephone call. This allows persons who travel to access their ISP for email and Internet services without incurring long-distance charges.

Organizations with Local Area Networks (LANs) enjoy high quality graphic and video resources. When these are accessed via POTS, screens build slowly and videos are abbreviated to a series of still pictures. In some instances the audio is broken and unusable. Increasing bandwidth using multiple telephone lines and/or using digital circuits of greater bandwidth such as ISDN and T1, solves these problems.

Connections through television cable or satellite and a lower cost telephone service called Digital Service Lines (DSL) is now making quality Internet and communication services available for home-offices and for individual users.

Increased traffic on telephone circuits led to tremendous growth of infrastructure in the western world in the 19909s. This is now occurring worldwide with growth focused in economically disadvantaged countries. Countries such as Malaysia, Indonesia, Africa and China have recognized the value of the Internet for education and for commerce and are installing large-scale fiber networks.

DEVELOPMENT OF TWO-WAY VIDEO

Broadcast radio and television have been used for education from their inception. In the 1962 the FCC assigned Instructional Television Fixed Service (ITFS) broadcast frequencies for educational use with provision for two-way talkback using FM frequencies. ITFS technology provided low-cost high-quality broadcast video and sound for sites within line-of-sight of the transmitting antenna. The FM talkback was little used because it was unreliable and not cost effective. Instead, telephone callback using regular telephone lines or 1-800 toll free lines provided this function.

In the late 1980s, two-way television over telephone lines was initiated using digital compression of audio and video. Video quality was dependent on digital telephone lines and greater bandwidth. One or more ISDN lines of 128-kilobit (kb) bandwidth enabled point-to-point connection cameras and TVs. Computers could be attached to these systems for PowerPoint and similar presentations. Multi-point systems enabled connection of multiple sites. Bridging services were set up to enable connection of sites operating at different bandwidths.

The two-way video signals were multiplexed with other telephone circuits, and were subject to the limitations of older switching equipment, improperly programmed routers, and connection through multiple telephone companies. Overloaded telephone circuits would result in breakup or loss of picture or even sound. Improved infrastructure has minimized these problems, but the cost remained high so it was cost-effective only where it saved extensive travel cost as in training, product rollout, and preliminary interview of a job candidate in another part of the country. Where more than 20 sites were involved and return video was not needed, satellite was more cost effective.

Streaming video, two-way video on the Internet, and expanded bandwidth for Internet connections opened an alternative avenue for two-way video. For one-to-one communications, two-way video was an inexpensive addition to personal computers, especially those already equipped for multimedia. Improved compression algorithms, streaming video, and DSL connections have improved these systems, and even 56K modems on POTS lines can give small but acceptable images with good quality sound. Bridging equipment for multi-point connections has been achieved at low cost using computer software such as that marketed by White Pine for CUSee-Me.

COMPUTER BASED COURSES FOR DISTANCE LEARNING

Competing standards groups and competing industries realized that the growth of two-way interactive video was seriously impeded by incompatible technologies. The move started toward global standardization comparable to the ISO movement in industry. The education community breathed a collective sigh of relief as cross-platform standards relieved the economic stress of incompatibility and ensured error-free transmission across telecommunication systems and networks.

A. Physical distribution of materials

Interactive multimedia programs can be distributed on physical media such as diskettes, CD-ROM and DVD. These materials may originate as text, PowerPoint presentations, multimedia, and video courses. Using traditional methods of marketing and distribution, the reproduction, marketing, and distribution costs are high, and products may require 18 months to reach their market peak. The typical marketing cost for a physical medium is at least as great as the production cost. Using Internet promotion and mass marketing, production and distribution cost can be greatly reduced.

B. Electronic distribution

Materials on the Internet are essentially self-marketing, and it is anticipated that cost recovery and profitability can be rapidly achieved. Except for expensive broadband systems, multimedia must be scaled down to effectively share network bandwidth and ensure reliable and responsive performance. High-end users can expect fast response times with excellent graphics and acceptable sound and video. As the network load increases, video is abbreviated or eliminated, sound breaks up and may become unusable. Low-end systems (telephone with modem) reliably present text with limited graphics. With 56K modems, sound accompanies text and graphics and limited video is possible. DSL provides high-quality high-speed access

Several methods are used to economize on bandwidth. Compression removes redundant data and requires a matching CODEC (COder-DECoder) at each end of the transmission line. These items usually require a special modem to be installed in the computer. For video, reduction in image size, frame rate, colors or grayscale limits the data rate so that picture and sound are within system limits. On busy networks, video frames may be lost.

With improved telecommunications and recording media, systems with lossy compression such as MPEG-1 (designed for CD-ROM) and ISDN (128K digital phone line) are rapidly being displaced. The best system currently available for full-screen full-motion video is MPEG-2. It is beginning to replace the two-way video systems using telephone lines and satellite. It is also available on DVDs and on digital broadcasting systems designed for High Definition Television. MPEG-3 is under development.

DSL is providing a lower cost broadband connection for internet and video, and Internet-2, a much more powerful network, is connecting major universities through the United States.

C. Interactive Computer Options

Good course design requires variety and change of pace (see section on Learning Styles in the University of the Future, February 1996). There are many options for interaction:

Real time options:

chat sessions (group participation with text)
computer conferencing using shared whiteboards and shared applications
desktop conferencing using audio and video alone
desktop conferencing using audio and video

Asynchronous options.

email
bulletin-boards
listservs
forums
interactive multimedia

Well designed distance learning lessons and courses will combine these options based on student and subject matter requirements. Real time interaction is preferred for advising, tutoring, and direct instruction.

D. Internet Course Production:

Any distance learning course involves design, testing, production, delivery, and management costs. It also requires specialized personnel, equipment, authoring programs, and software to achieve quality at an affordable price. It is rare to find a faculty person with a course that will stand-alone. In some instances the course may be useable by another instructor, but re-manufacturing will be needed to effectively integrate those live elements provided by the teacher into the program. In addition to motivation and being pedagogically sound, text, visual, and audio components must be of professional quality

Since a sizable investment is involved, market research is well advised. First define the product based on a needs assessment. How does it relate to existing courses? Does anything like it already exist? What are people willing to pay? How many sales can be made in the first year? How long will it take to reach profitability? These are hard-nosed decisions. Stable subject matter is desirable for a product to have a useful life of three before revision or retirement. Special production and marketing procedures are required when the content is in a state of flux.

E. Instructional Design

Motivation and interaction are key components whether the learner participates in a "live" class at a distance or using pre-prepared lesson materials on the Internet or a CD-ROM. Very often the distant student has a high level of need and / or intrinsic motivation or that person would not have enrolled in the course or the program. It is important to fuel and maintain the high motivation with a rich communication environment that facilitates sustained two-way communication and learning.

Why is interaction important? How do we know how well we have learned? Feedback is an important part of the communication / learning process. In its simplest form it tells us we are "on track" - as in a simple test. A more sophisticated use is for diagnosis and prescription so we can bypass familiar material and achieve mastery with new learning.

Dialog is an excellent form of interaction because the learner is encouraged to contribute his or her own ideas rather than conform to a set agenda. Games and simulations are useful to learn complex skills and for problem solving. The important aspect from the point of view of the instructional designer is to provide appropriate forms of feedback to stimulate learning, guide the student, correct errors, encourage students to explore, create, and collaborate with others in the learning process, and be effective in communication and dialog.

Research by Keller showed that students require clear objectives, a strong sense that the learning has value, and that he or she is capable of mastery. These three items are prerequisites to quality organization and presentation of the lesson content and experiences. This is true for a wide variety of course structures, teaching styles, and learning styles. It is true for traditional teacher directed courses, for inquiry based learning experiences where the student¹s products become the course content, for group experiences where team members collaborative on a project, and creative learning where new knowledge is generated by an individual or group process. Structured presentation can facilitate learning, as does appropriate use of graphics, sound, animation, videos, models and mockups, simulated and real experiences. The instructional designer should favor cost-effective use of these resources where cost is measured in terms of learning effectiveness. Objectives focus the direction, levels, and depth of learning. Cognitive, affective and psycho-motor dimensions of the Bloom Taxonomy provide guidelines for shaping clear objectives that ascend to higher integrated levels of learning and focus performance dimensions of how well and under what conditions the outcomes will be demonstrated.

F. Instructional Design Models and Teaching Models

Traditional instructional design models focus on the stages in developing instructional materials. Examples include the linear Instructional System Design (ISD) model developed for military training, the Kemp model that introduced the cyclic and reiterative nature of production, and the ADDIE (Assess, Design, Develop, Implement, Evaluate) model that is a simplification of the Kemp model. Keller¹s ARCS model focuses on the learner and learning. It integrates the domains and levels of the Bloom taxonomy of learning to focus on Attention, Relevance, Confidence, and Satisfaction. Beyond relevance, it moves the focus away from cognitive to affective aspects of learning. Research using Keller¹s model has been used to prioritize the needs of distant learners as mention earlier. The most powerful instructional design model that addresses the role of interaction per se in the learning process has been developed by Dr. Guy Bensusan at Northern Arizona University.

Teaching models addressed by Bruce Joyce define interaction in many forms and at many levels.

Traditional directive teaching models focus on setting-the-stage (objectives), instruction (content), guided practice (application), closure (testing), and independent practice (repeat without the teacher). As we expand beyond direct instruction, new elements are added to the teaching- learning process.

In Cooperative learning students are assigned roles in group-activities that require mutual reliance and skills in working together to achieve the lesson outcomes (interacting with each other and with ideas).

Inquiry learning requires students to confront and solve a problem or disparate event by gathering data, establishing facts, building concepts, hypothesizing and testing causal relationships, and formulating rules and explanations (interacting with the problem, establishing hypotheses, gathering and interpreting evidence to solve the problem).

Creative learning develops our ability for free association and divergent thinking (using the creative part of our minds). Mind-mapping is an individual method for discovering and structuring ideas, brainstorming is an intense and exciting group method, while clustering facilitates organizing and prioritizing information.

When we combine direct, inquiry, interactive, and creative teaching methods within a lesson, we call this Teaching Around the Wheel. It better serves the needs of learners with different learning style preferences, adds interest, and develops a wider range of learning skills.

When we combine instructional design, teaching, and learning models, we arrive at a multi-dimensional model. In its simplest form, it is a cube that combines design and production on one face (ADDIE), instruction on a second face (domains and levels / ARCS / teaching models), and learning on the third face (learning styles and outcomes). The cube has considerable value in modeling the complexity of the process. What is needed is a model that will guide the design process. If the dimensions of the cube were properly chosen, each block or cell within the cube would represent a design solution for each unique teaching and learning requirement.

G. An Alternative Focus

Bensusan provides a different focus. He does not require all teaching to be direct teaching or all learning to be interactive. He provides the materials of instruction to the students in advance of each class. Students determine whether to learn independently or in groups, which media and references to use, and the time and place for learning. The class is a culminating event where the students interact with the ideas and with each other to take learning to the next level. Bensusan allows learning to happen, facilitating it rather than controlling it. In this way, students are liberated from dependency, develop personal confidence, have a feeling of accomplishment, and acquire skills for lifelong learning. The process of learning is carried on in many ways and at many levels to achieve the final goal. Bensusan uses this method for distance learning.

For the instructional designer, Bensusan¹s method is to create a resource rich learning environment where the student has options to learn and be evaluated in a variety of learning styles. The class is not a data dump, but a learning situation where students who have studied the materials can engage in verbalizing and manipulating the many parts to the puzzle.

H. Instructional Design for Developing Internet Lessons

A template simplifies the design and production. However, it is not consistent with what we know about good teaching that encompasses a broad range of learning styles, skills, content, and outcomes. The computer may compel us to interact for long sessions, but the best learning involves a variety of experiences that are appropriate for the kind and level of learning involved. Learning begins with clear objectives that the learner considers to be valuable and achievable. Learning us supported by a rich learning environment combining a series of presentations, projects, physical and mental activities, individual study, and group interaction. Within the broader framework setup by the instructor, learners set their own time frames, learning styles, and methods of evaluation. They seek the assistance of others and monitor their own progress. The class is the culminating event where they test and refine what they have learned through interaction with our peers and instructors. This class may be live, interactive video, or asynchronous learning through computer conferencing.

Text is not enough. Where appropriate we add graphics, sound, and video. The instructional designer must work with the limitations of the chosen medium, or combine media to achieve the desired result at an affordable cost. If a template is used, it becomes the continuity device to combine different lesson elements. The designer becomes the master teacher who breathes life into the learning experiences for a diverse group of students and teachers.

The instructional designer has to know his target audience and subject matter. He must combine the motivational elements of a successful writer as he articulates his cast (teachers and consultants) and crew (artists and technicians) to produce lessons that consistently achieve the desired learning outcomes. He orchestrates the elements of each lesson for a novice - the learner - to conduct according to his or her own preferences and style. The virtual teacher serves as a catalyst, supported by a cadre of counselors, advisors, consultants, mentors, tutors, instructors, and students. They collectively provide interaction, stimulation, guidance, and evaluation.

The distance learning course of the future is like an automobile which integrates the best thinking of its designers, instructors, and producers into an independent means of transportation that will take us to our learning destination.

I. Learning Styles and Evaluation

Traditional methods of evaluation include True-False, Multiple Choice, Matching, Short Essay, and Research Paper. These fit with the concept of learning as knowledge, and assume the relevance and validity of the questions as representative of learning. The results may be modified by attendance, punctual presentation of deliverables, and special projects. The result is a tally of numbers used to assign students into boxes labeled A, B, C, D, and F. It is assumed that instruction is a constant and that the student scores are the variable.

A more modern approach is criterion based testing where the course objectives define an outcome or performance, conditions under which the performance is measured, and a standard. In traditional evaluation, instruction is a constant and learning is the variable. With criterion-based testing, learning is a constant and instruction is the variable. Instruction continues until the standard is reached.

In criterion or standards based learning, outcomes are measured by a project, portfolio or performance that integrates the essential elements of the course. Alternative methods of evaluation include games and simulations that demonstrate a spectrum of the learner¹s abilities and accomplishments. The goal is to have as many students as possible achieve the standard, and it should be a high standard. Failure can be minimized, and meritorious performance (over and beyond expectations) can receive special recognition.

If learning styles determine our approach to learning, then those same traits of personality and learning-style-preferences influence our performance with alternative modes of evaluation. Traditional testing may not fit well with non-traditional learners, and vice versa. Just as it is desirable to have alternative versions of multiple-choice tests for use in traditional learning situations, non-traditional students should have options that reflect their learning style. The inquiry-based learner should research and solve a new problem, the interactive learner should have individual and group performance and outcomes from collaborative projects, and the creative person should be given latitude to do significant creative thinking, production and presentation of their ideas.

How then, with such diverse methods of testing, do you rank and grade the students? You don¹t! You determine when the course outcomes have been achieved to the required standard. If the student has not achieved that standard, he or she continues to work, with the instructor¹s support, until the standard is reached. Recognition of individual differences and learning styles can substantially improve success rates in educational settings, and eliminate the premature and inappropriate branding of students from differing backgrounds at different maturational levels.

J. Implementation for Large Numbers of Distant Learners

Whatever methods of teaching and evaluation are used, they must be reliable and effective. Like computer software and mass produced commodities, they must be designed and tested to ensure that they work well under a great variety of conditions. Federal labeling guidelines may even require us to state the spectrum of results to be expected for specified groups of students. This is not to be discouraged. It requires the development of the sciences of instructional design, teaching, and evaluation beyond what is presently implemented in our colleges and universities. It challenges us to set up high standards and to achieve them. It moves emphasis from teaching to learning, and control from teacher to learner.

We should surround ourselves with examples of great teachers and teaching, checklists such as the taxonomies and Gagne¹s Ten Steps. We must ourselves become part of the process of inquiry and interaction and creativity that breaks the lockstep of direct instruction and invites the non-traditional students back into our schools and universities.

There will always be great lecturers, great researchers, great humanitarians, and creative geniuses. We need them all to maximize the effectiveness of the educational process. We must develop learning environments that are responsive to the needs of a diversity of students, geographically dispersed, with a wide range of learning styles.

About the Authors
Don and Elizabeth Perrin are Managing Editors of USDLA Publications including Education at a Distance ­ ED Journal and ED Magazine. They are currently working for the Ohana Foundation in Honolulu and Cupertino developing interactive media for grades K-12. They may be accessed by email at eperrin@pacbell.net or by cell phone at 909-236-2658

Tutorial papers will be published periodically to help readers who are new to the field of distance learning.