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DISTANCE EDUCATION AT A GLANCE
GUIDE 10: Interactive Videoconferencing in Distance Education
Why Interactive Videoconferencing The
Technology of IV Advantages of Interactive
Video Limitations of Interactive Video
Types of Videoconferencing Systems Designing
Instruction for Interactive Video Instructional
Strategies Training for Instructors and Students
References For Further
Information
Interactive Videoconferencing (IV) is an effective tool that may be used
in distance education settings. This system can be integrated into the
distance education program with minimal adaptation to the curriculum and
course and is designed to support two-way video and audio communication
between multiple locations.
Most IV systems utilize compressed digital video for the transmission
of motion images over data networks such as high capacity Integrated Services
Digital Networks (ISDN). The video compression process decreases the amount
of data transmitted over the lines by transmitting only the changes in
the picture. By minimizing the bandwidth required to transmit the images,
video compression also reduces the transmission cost.
Interactive videoconferences are often transmitted on dedicated T-1 phone
lines. These high speed lines are very effective for videoconferencing,
but they are typically leased circuits with an expensive monthly cost.
The fixed monthly charge is usually based on distance, not usage. Therefore,
the cost effectiveness of IV systems increases with use. Interactive videoconferencing
systems can operate at different data rates, at various fractions of T-1
capacity, enabling the transmission of multiple simultaneous videoconferences
over the same T-1 circuit. An IV system can also share a T-1 circuit with
other digital data uses such as Internet transmissions or file transfers.
Point-to-point
Interactive videoconferencing is commonly used to connect two locations
using sophisticated computer technology. The core of IV is the codec (coder/decoder).
This is the electronic device that transmits and receives the video signals
that the class members will see on their television monitors (Galbreath,
1995). It may be easier to think of the codec as an extremely sophisticated
modem. A modem takes digital data and transmits it over regular phone
lines. The codec takes analog signals, compresses and digitizes them,
and transmits the signals over digital phone lines (Woodruff and Mosby,
1996).
Other types of equipment, such as television monitors, are needed to
make IV successful. In addition, various forms of instructional technology
can be incorporated into IV, including video cassette recorders/players,
microphones, cameras, and computers (Reed and Woodruff, 1995).
Point-to-Multipoint
Some systems are also capable of simultaneously connecting more than
two sites through the use of a multi-point control unit, or MCU. Multi-point
conferencing can be effective although the scheduling, technical, and
logistical dimensions of MCU conferences can be imposing.
Dial Out Capability
A relatively new “dial out” feature, allows the use of multiple telephone
lines to connect two or more sites in the same conference. Simultaneously
accessing multiple lines may be difficult in small areas. In addition, the
cost of the telephone line usage may be prohibitive since the cost of the
call would be multiplied by the number of lines utilized in the conference.
Interactive video can be effective because it:
- Allows “real time” visual contact between students and the instructor
or among students at different sites.
- Supports the use of diverse media (Reed and Woodruff, 1995). Blackboards,
handwritten documents, and videos may be incorporated at all sites.
- Enables connection with experts in other geographical locations (Reed
and Woodruff, 1995).
- Can provide access to at-risk or special needs students (Woodruff
and Mosby, 1996).
- Provides additional access to students at remote sites.
As with any technology, interactive video has its limitations:
- The initial cost of the equipment and leasing the lines to transmit
conferences may be prohibitive.
- Companies which produce codecs have each developed unique methods
of compression which are incompatible, although protocols have been
established to allow communication among brand names. However, this
“universal standard” compromises resolution and quality to a certain
degree.
- Unless a strong effort is made by the instructor, students not located
with the instructor may remain uninvolved in the course.
- If visuals, like handwritten or copied materials, are not properly
prepared, students may have a difficult time reading them.
- If the “pipe” that carries the transmission among sites is not large
enough, the students may observe “ghost images” when rapid movement
occurs in “real time” (Reed and Woodruff, 1995).
- If the system is not properly configured, class members may observe
an audio “echo” effect (Reed and Wooduff, 1995). The result is audio
interference that detracts from the learning environment.
- Small room videoconferencing. This system is designed primarily for
small groups (1-12 participants) at all sites seated around a conference
table (Woodruff and Mosby, 1996).
- Classroom videoconferencing. This type of system usually uses high
quality AV components, codecs, and an interface that allows all participants
to be seen on the monitors.
- Desktop videoconferencing. This system utilizes a personal computer
and videoconferencing software. These systems are less expensive, but
offer limited resolution. They are most effective for individual and
small group use (Woodruff and Mosby, 1996).
When designing instruction to be delivered over IV, the instructor should
focus attention on all students, not just those at the “home” site. Lessons
should incorporate a variety of activities for all students at the various
sites. Use small group activities, student presentations, and an occasional
break to add variety to the lesson. As a rule of thumb, instructors should
change instruction methods every 10-15 minutes. In other words, switch
from lecture to question-answer to small group activity on a regular basis.
It is often helpful to bring guest lecturers into the classroom. It may
also be helpful to have guest speakers at one or more of the distant sites.
This will encourage involvement of the distant students, as well as allowing
the students at the origination site to “see what it is like” to have
the teacher at another location.
When preparing class visuals, keep in mind that small fonts and light
colors do not show up well over the monitors. A variety of formatting
will also assist in maintaining student interest and attention. When formatting
visuals, be sure that they will fit on the television monitor (Reed and
Woodruff, 1995).
Establish Class Expectations
In the distance education classroom, some students may adopt the “TV”
attitude, expecting the course to be entertaining, not educational (Reed
and Woodruff, 1995). Address this attitude through well planned and focused
presentations with emphasis on teacher-student interaction.
Reduce Distractions
Students should also be forewarned to minimize extraneous noise and activity
(Reed and Woodruff, 1995). Both detract from the quality of the course.
Use Variety and interaction.
The instructor should begin the course by preparing the learners for
an active experience. Interactive videoconferencing is interactive, unlike
regular television, and students can make the class much more interesting
by being actively involved.
Encourage Dialogue
By asking questions and noting body language, instructors can ascertain
the interest and comprehension of the students at both all sites. This
kind of attention will make all students feel more comfortable.
It is important that an instructor be taught how to use all features
of the equipment. A short session (30 minutes) should be sufficient to
give the instructor a “hands-on” overview of the equipment features. It
would also be helpful to provide the instructor with a quick reference
sheet outlining major functions.
Some of the critical operations that an instructor should be capable
of performing are:
- Turning on the codec and the monitors.
- Dialing the distant site(s) to establish a link.
- Controlling camera focus and field at the origination site and at
the distant site(s).
- Adjusting the volume to an acceptable level.
- Dialing out to a remote location.
- Selecting the appropriate data rate.
- Re-setting “echo canceling” capability.
- Switching to and from the document camera.
- Switching to and from the computer output.
- Utilizing a computer to generate and display multimedia presentations.
- Using the VCR to broadcast a video for all locations.
- Terminating the link with the distant site(s).
- Shutting down the equipment.
Some institutions have technicians who will assist the instructor in
setting up or monitoring the videoconference. However, the instructor
should still be aware of the process because the technician may not always
be available.
Student training may also be critical since they may be called upon to
operate the equipment if the instructor is at another site, is unavailable,
or if a guest speaker needs assistance.
Interactive videoconferencing can be an effective instructional tool
for the distance educator. As with other technologies, its usefulness
is directly related to the instructor’s understanding of its benefits,
limitations, and utilization strategies.
Galbreath, J. (1995) Compressed Digital Videoconferencing. Educational
Technology, 35(1), 31-38.
Glossary of Terms. (1996).
Reed, J. and Woodruff, M. (1995). Using compressed video for distance
learning. http://www.kn.pacbell.com/wired/vidconf/Using.html.
Woodruff, M & Mosby, J. (1996). A brief description of videoconferencing.
Videoconferencing in the classroom and library. http://www.kn.pacbell.com/wired/vidconf/description.html#what.
This guide is one in a series developed by
Barry Willis and the University of Idaho Engineering Outreach staff
highlighting information detailed in Dr. Willis'
books, Distance Education–Strategies and Tools and Distance
Education–A Practical Guide. Other guides in this series
include:
1 Distance Education: An Overview
2 Strategies for Teaching at a Distance
3 Instructional Development for Distance Education
4 Evaluation for Distance Educators
5 Instructional Television
6 Computers in Distance Education
7 Print in Distance Education
8 Strategies for Learning at a Distance
9 Distance Education: Research
10 Interactive Videoconferencing in Distance Education
11 Distance Education and the WWW
12 Copyright and Distance Education
13 Glossary of Distance Education Terminology
This guide was originally edited by Tania
H. Gottschalk, University of Idaho Engineering Outreach
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