Streaming Media in Higher Education: Possibilities and Pitfalls
You have to admit: streaming media is sexy.
The immediacy of the moving image and the impact of the human voice is powerful.
Streaming media can be richly communicative, tapping in to our profound ability
to learn from sensory information. Humans are social animals, and we gain much
of our initial understanding of others through our visual and auditory capacities.
In the realm of online education, it is important to tap these abilities even
across the distances that separate participants. Seeing other participants,
or hearing their voices, provides a presence and potency that text alone cannot
match.
Streaming media has been offered up as a solution to a wide variety of problems:
how to connect students and faculty at a distance, to deliver core course content,
and where to find new sources of revenue for cash-strapped institutions. Without
proper consideration of the audience receiving streaming media, however, the
promise of this technology might quickly turn into frustration for all involved.
Knowing your audience and the limitations of its Internet infrastructure is
key to creating a reliable streaming media delivery system. You or your institution
do not want to invest hundreds or thousands of hours in developing content only
to find out that your students cannot receive that content because of network
and connectivity limitations. It's best to tackle these issues head-on, before
you begin to develop content. Creating a rewarding online learning experience
is, after all, the primary goal.
Grape Through a Straw
Bandwidth is everything when it comes to streaming media. Regardless of what
kind of media you are streaming, whether text, data, audio or video, it is the
available bandwidth that will determine the end user's success or failure in
receiving your material. Every step of your production and delivery process
must keep this simple fact in mind.
When most people think of streaming media, they think of streaming video: images
of faculty lecturing in front of the class, of medical procedures performed
by experts, or of educational documentaries, to name a few. These are all good
ideas to varying degrees, but video is enormously bandwidth-intensive. Instead
of sending a single, still image to an end user's computer—as you would for
a graphic on a regular Web page—video requires a rapid succession of images.
Any change from one frame of the video to the next requires additional data
to be sent to the viewer's computer. For a student at home on a 56K dial-up
modem, watching a section of a documentary video for a class would be as easy
as sucking a grape through a straw. There would literally be too much data to
fit through the tiny pipe that connects her computer to the Internet and the
media server.
A significant amount of bandwidth is also required to play back video at a
size that is acceptable to most viewers. You may be able to get a video to stream
smoothly to a user on a 56K dial-up connection, but will anyone want to watch
it if the image is barely larger than a postage stamp? Even high-speed networks
are hardly immune from the problems with streaming video smoothly.
You and your
students may all be on campus, using your school's network, but so is everyone
else at your school. A 10Mbps connection to the Internet sounds like a wealth
of bandwidth until you remember that you and the rest of the people at your
institution are all competing, simultaneously, for a piece of that same pie.
What may be available, ultimately, is a bandwidth allocation that is much, much
smaller than you would expect.
Generally, a user will be able to tap a little more than half of the theoretically
available bandwidth, assuming no major network traffic or other slowdowns. Keep
in mind that while there is generally much more bandwidth available to a local
area network connection, those connections tend to be used by hundreds, if not
thousands, of users at the same time.
| Theoretical vs. "Real World"
Data Rates |
| Connection
Speed |
Theoretical
Speed |
"Real
World" Speed |
| 28.8Kbps (modem) |
3.6KB/sec |
2.3KB/sec |
| 56Kbps (modem/wireless) |
7KB/sec |
4.7KB/sec |
| 256Kbps (DSL/Cable) |
32KB/sec |
21.4KB/sec |
| 10Mbps (LAN) |
1,280KB/sec |
858KB/sec |
| 100Mbps (LAN) |
12,800KB/sec |
8580KB/sec |
|
|
The good news is that help is available in overcoming these bandwidth constraints. Modern streaming media codecs (COmpressors/DECompressors) do an excellent job of compressing the amount of data required for a given stream down to the smallest possible amount. The latest codecs for Microsoft Corp.'s Windows Media Player, RealNetworks' RealPlayer and Apple Computer's QuickTime Player—the "big three" in streaming media—can deliver VHS-quality video and CD-quality audio at remarkably small data rates. But despite these advances, the pedagogic value of streaming video or any other kind of media must be weighed against the end user experience of receiving that media over potentially limited connections to the Internet.
The Right Tool for the Job
At this point, you might think that we at the Johns Hopkins Bloomberg School
of Public Health are dead set against using video in online learning. That is
certainly not the case. Picking "the right tool for the job" is critical in
meeting both our pedagogic and technical requirements. Streaming video can be
an excellent medium for showing the change of environments over time, explaining
the details of a medical procedure, or giving the faculty teaching in online
courses a more "human" presence on their course Web sites. The medium is not,
however, good for talking heads or re-purposing in-class lectures.
While the image of an instructor's head and upper torso can be quite useful in conveying more of a person's personality to online learners, at what point d'es the "talking head" stop adding to the learning process and simply continue to suck up valuable bandwidth? Shooting in-class lectures and re-purposing them for Web broadcast may be acceptable for student review, but serious quality control must be in place for students who are learning entirely online.
Audio Plus PowerPoint
Instead of shooting in-class lectures, or providing a talking head along with
PowerPoint slides, we have found that audio (no video) combined with PowerPoint
slides is not only as educationally effective when it comes to lectures, but
that it provides a significantly superior qualitative experience with minimal
network overhead. Using a small piece of video as an introduction to a lecture
is certainly worthwhile, but the video introduction should be short and to the
point. Always use video appropriately and your online learners will be much
happier.
But while using a combination of slides and audio is a highly useful and effective, there are some important issues to keep in mind:
- Record in a studio setting, not in the classroom. Anything recorded in the
classroom and rebroadcast in an online course reeks of "second-hand material"
to online learners.
- PowerPoint slides delivered as part of a streaming lecture presentation
will not display at full screen size, but rather at a much smaller size—usually
around 400 x 300. The smaller slide size is, again, a function of bandwidth
limitations. Thus, a table on a slide that looks fine projected in the classroom
may quickly become illegible when output for a streaming lecture presentation.
- Consider making two versions of each presentation: one for high-speed connections
and one for dial-up connections. If your media player supports SMIL (Synchronized
Multimedia Instruction Language), as the RealPlayer and QuickTime Player do,
you can use the SMIL tag to check the user's connection speed and
provide an appropriate bandwidth-intensive presentation for them.
- Always allow a minimum of 15 seconds between slides in your presentation.
This will allow slides in a low-bandwidth presentation enough time to fully
download to the student's media player before display.
Lectures may be the most common form of instruction in higher education, but lectures alone may be too passive a medium for some learners and not the best way to convey all ideas. You might not think of Macromedia's Flash as being "streaming media," but with the inclusion of audio and video streaming in the latest Flash player, it is time to rethink that position.
Flash movies have always "streamed," in a sense, during playback. Flash movies begin playing back as soon as enough data has been received on the student's computer (commonly referred to as "progressive download" rather than true streaming). In Flash MX, however, you can now stream video or audio from Macromedia's Flash Communication Server inside of your Flash movies. As Flash movies can hold a great deal of interactive code—you can actually build complex applications within Flash MX—you can now combine the power of streaming media with the low-bandwidth delivery and high interactivity that Flash provides.
While the mixture of pedagogic approaches and small file sizes that Flash allows is exciting, building online learning materials in Flash MX can be time consuming. Although Macromedia smartly provides a series of eLearning templates (for quizzes and the like) along with Flash MX, most schools will need to create their own content from scratch. Greater technical skill is required to build richly interactive Flash applications than to create simple streaming lecture presentations. The cost of finding and hiring qualified developers to build the Flash applications that you require may be beyond your budgetary means. Nonetheless, Flash provides a compelling medium for delivering even small simulations or animations of how data changes over time.
Stumbling Blocks
While the truly effective use of streaming media can be achieved with even limited
bandwidth, there are a few major stumbling blocks that any institution using
streaming media in online learning must face. First and foremost is cost: Producing
streaming media is much more resource-intensive than producing text or still
images alone. From setting up a studio, to the additional time faculty will
spend preparing and recording lectures for online delivery, to the cost of streaming
media servers, the process of delivering course content in streaming format
adds up quickly.
Time is the one thing that all faculty have precious little of, so maximizing their use of that time is critical. Building an infrastructure to make things run as smoothly as possible for faculty to deliver course content in streaming format is, while expensive, critical. Few faculty will agree to a delivery strategy that is resource intensive and exhausting.
Acquiring the streaming media player itself is another obstacle that users in your online environment will face. Although the Windows Media Player comes bundled with most recent versions of the Windows operating system, many users will still have to download the media player if you use the latest and most bandwidth-friendly codecs—an experience that can take up to a few hours for students on dial-up connections.
Further, not all streaming media players support the same types of streaming media. Windows Media Player d'es not support streaming Flash animations and tends to work best (not surprisingly) only on the Windows platform in conjunction with the Internet Explorer browser. The QuickTime player supports the broadest range of streaming media types but is the largest of the "big three" players to download. The RealPlayer is a flexible player, which can handle Flash animations and the latest extensions to SMIL, but the advertisements presented in the free version of the player are a great annoyance to many faculty and students. The Flash player is a very small download, but developing in Flash is the most time-intensive of all media players.
You will need to weigh the features of each player against the issues each player presents for your audience. Supporting more than one player requires additional resource allocation, and, therefore, is more expensive than supporting a single player. We have standardized on the RealPlayer because of its rich feature set and its ability to combine a wide variety of media via SMIL.
Finally, keep in mind that streaming audio and video is not easily searchable. There are tools available that can search streaming media files, but they are neither simple nor inexpensive. If having the ability to search through all content available to students in your class is a key requirement, streaming media may not be for you.
New Frontiers
The emergence of mobile and collaborative computing have had a definite impact
on streaming media. The promise of mobile computing and true "anywhere learning"
is enticing, but the key issue of bandwidth and resource availability on the
student end figures even more prominently in the mobile environment. Handheld
devices and laptop computers with wireless network cards tend to have access
to less bandwidth than even dial-up modem users, so if you plan to deliver streaming
media to these audiences, use audio only. Also, keep in mind that many handheld
devices cannot play audio of any kind, so be sure to know your audience well
before trying to deliver streaming media on handheld devices.
Collaborative computing, where multiple users work on the same document or project at the same time, allows for high levels of interaction between students in an online program. But finding the tools to achieve the goals of collaborative computing can be difficult and expensive. Recent developments in this area have brought new tools which combine live streaming audio or video with data sharing and, in some cases, application sharing.
Products from WebEx, Centra, HorizonLive, and elluminate provide for collaborative computing focused on documents, while Macromedia's new Flash Communication Server focuses on data sharing. With the Flash Communication Server, you can build applications that combine audio and video conferencing with real-time simulations or data sharing activities within the Flash player. As the Flash player is a small download and works across a wide variety of computing platforms, this creates a particularly exciting area for new development.
Streaming media is a rich and powerful tool for delivering instruction to online learners. With the right up-front planning and a mindful eye toward bandwidth consumption, students in your online learning programs can reap the benefits of streaming media while avoiding many of the common frustrations associated with audio, video, and other forms of media on the Web.
