Video Conferencing for Teaching and Learning
by Prof. Jim Lengel, Boston University College of Communication
The arrival of broadband access in more and more schools and homes, and the
invention of new technologies for compressing and streaming video over the Internet,
have combined to make it easier then ever to use video for teaching and learning.
This article looks at video conferencing in particular -- the use of
live video to enhance learning. We'll look at its history, its technologies,
and its applications to the work of a teacher. But first, a glimpse into some
classrooms:
Picture this
- The third seal from the left -- the students had named him Oscar -- was
about to move across the rock and challenge the authority of the old bull.
The students in this Iowa classroom were observing first-hand, in real time,
the activities of aquatic mammals off the coast of California, thanks to a
live video feed from a science observation post over the Internet and into
their classroom.
- Susan's treatments put her in the hospital for a long stay this time --
two months. But she kept in close contact with her teacher and fellow students
through instant messenger. From her hospital bed, she could type her responses
to the teacher's questions; she could hear the discussion in the classroom
and speak up when it was her turn; she could also, if she chose, see the class
and let them see her. All using a simple laptop computer with a tiny camera.
- He was the world's expert on King Lear, but he was in England and the class
of 11th graders was in Florida. As soon as school opened, they fired up the
classroom computer and navigated to the site where the lecture would appear.
There he was, live and in real time. The video cut back and forth from the
lecturer to the players who were acting out the scenes he analyzed. The students
typed in questions now and then, and heard the lecturer respond to them.
- The debate was in full swing. The students in Saskatchewan took the affirmative.
Though they were animated and seemed eloquent and convincing, nonetheless the
students in Arizona found their logic to be suspect. They took notes as the Canadians presented.
In their rebuttal, the Arizonans, one by one, came forward to the camera, and refuted
the Canadians' arguments, and watched them furiously taking notes. This debate
was held live between the schools, using Internet video.
Not your father's videoconferencing
These are not futuristic scenarios -- these activities are happening right
now in schools around the world. They all use some form of videoconferencing
to enhance teaching and learning, and doing it simply and cheaply using classroom
computers and the Internet. Videoconferencing has been available since the 1960's,
but has always been to expensive and too unwieldy to be used in classrooms.
In the beginning, you needed two television studios, two transmitters, and two
receivers to conduct a videoconference like the ones described above -- impossible
to fit in a classroom, and hundreds of thousands of dollars to set up. One-way
transmissions were possible, using satellite networks through which many classrooms
could view a single event, but these were neither interactive nor everyday events,
and cost thousands to produce.
In the 1980's interactive point-to-point videoconferencing came along using a special
camera plus TV combination at each site, connected over specially-configured
telephone lines. This brought the equipment costs down to under $100,000, and
the transmission costs to under $500 per hour, and allowed direct interaction
between the parties. But videoconferencing was still far beyond the capabilities
of everyday teachers.
Then in the 1990's the Internet came into schools and homes. We quickly figured
out how to send text to anyone at anytime over the Web, and later pictures and
MP3 music. For the first time, we had a multimedia network that could connect
us directly with any other classroom or computer. At very low cost. But video
and voice were beyond its capabilities.
The millennium brought video software into the mainstream of computing: all
of the new computers came equipped to show video and sound as well as text and
pictures. The new century also brought broadband to more and more homes and
schools, and spurred the invention of new compression and streaming technologies
that let that digital video travel through the Internet in real time. The last
two years especially have seen an explosion of video conferencing over the web,
based on these new capabilities.
How it works
If you and I want to videoconference, we each attach a video camera to our
computers, make a connection between us over the Internet, and begin to watch
and listen. It's that simple from a user's perspective. (I'm on sabbatical this
semester in France, while my daughters remain behind in Boston. We videoconference
every other day, with one click at either end. And I'm using a 4-year old laptop
at my end.)
When we connect, the video signal from the camera and its audio (any digital
video camera can be used), are compressed by my computer, and then immediately,
frame by frame, sent over the Internet directly to your computer, which de-compresses
them and displays them in a window on your screen. With a solid broadband connection,
the video is clear and the transmission delay is imperceptible.
Some video transmissions, like the seals on the rocks, are accessed through
a web site -- go to the site, click a button, and watch the video. Try
http://www.racerocks.com/. Conferences between individuals are most often
arranged through a directory service such as AOL Instant Messenger (AIM) or
Microsoft NetMeeting -- find your correspondent in the buddy list, click on
them, and begin conferencing. It's that simple.
Compressing video
The secret to making all this work is video compression. Your computer
needs very quickly to take a video signal from the camera that contains many
megabytes of high-quality information each second, and compress it so it will
"fit" through the bandwidth you actually have available (a cable modem
will provide about 500 kb, or half a megabit, per second). It does this by making
the video window smaller, removing some of the information, and reducing the
rest to a bare minimum. The more it compresses, the lower the quality of the
video. Between France and Boston, with a cable modem at both ends, we get quarter-screen
video with enough quality to see facial expressions and enjoy natural voices.
The development of video compression software has advanced significantly since
the turn of the century, with many companies competing to fit better quality
into less bandwidth. At the same time, the processing power and speed of even
the low-end computers enables them to accomplish this compression (and de-compression
at the receiving end) in real time. And most computers now include a FireWire
connector that can take digital video directly from the camera. So what was
once a technical experiment with lots of special equipment and a flock of engineers
is not a point-and-click operation.
What you can do
To experience the reality of live video, connect to a site such as Race Rocks
and watch the live video. You won't be able to talk back to the seals, but you
will see the possibilities. For a list of similar virtual video field trips,
see the information at http://ali.apple.com/ali_sites/ali/vft.html
To get started with interactive, point-to-point videoconferencing, follow these
steps:
- Make sure that your next computer has a FireWire connector and videoconferencing
software. Computers so equipped are available for less than $1000 today. The
software is free for downloading from the vendors, whose sites are listed
at the end of this article.
- Connect a digital video camera to your computer. A home camcorder works
fine. So do the little $100 clip-on cameras such as the Pyro Webcam or the
Apple iSight.
- Fire up the software. The most popular are Apple's iChat AV and Microsoft's
NetMeeting. (The Apple iChat is much easier to set up and configure.)
- Connect to a correspondent. With iChat, you can use your AIM screen name
(free from AOL) and get your correspondent to do the same. Use the AIM buddy
list to connect to each other. With NetMeeting, you'll need to know the IP
address of your correspondent, and vice versa.
- Watch and talk. With a good broadband connection, you should be able to
achieve a three-inch wide video window and good quality sound.
Once you've got it working, think of ways to apply this new capability to teaching
and learning in your classroom. Find live Internet video events in your subject
area. Conduct joint investigations between your students and students in other
schools around the world. Bring home-bound students, or experts from afar, as
guests into your classroom. Produce a news program and broadcast it to the kindergarten
classroom. The possibilities are endless.
To learn more
Ideas for Internet video in the classroom:
Videoconferencing products:
View Teaching with Technology Archive
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