Reliability is a vital requirement for a program of this kind. Most of us would consider canceling even a single class and sending the students home to be a major calamity. Yet streaming media classes involve a long list of hardware, (at least three different computers, networks, projector, camera, audio equipment, etc.) as well as a considerable amount of software. The failure of any part may require the class to be canceled. Recognizing this, from the beginning redundancy was made a primary goal.
Almost all of our equipment can be replaced on the fly. To verify proper operation of all equipment before class starts, the instructor's browser window loads on startup a "pilot's checklist". Like flying, the well being of the class depends on a lot of high tech equipment.
Unfortunately, there is not much direct control over failures at the client side. Computers crash, power outages occur, bottlenecks on the long network connection from the classroom to the students' homes can become saturated regardless of the speed of the connection, et cetera. To reduce the effect of such problems, full lecture notes are required. Students should have enough information to tide them over minor rough spots without having to fall back on the archived lecture. We do recommend that students reboot their Windows machines before each lecture, but many arrive at the last moment and do not.
To allow classes to be attended from low bandwidth locations such as student homes, the video window is small. It functions mainly as a pointer into full-size prepared lecture notes that are served to the students as web pages. We use a small video window and compressed audio, which allows us to reach our students through existing plain phone lines. Thus a student, local or online, can go almost anywhere in the world and keep up with the online classes. This gives the student the flexibility to use the most reliable connection.
The small bandwidth we use reduces the required resources even for higher speed connections. Although peak bandwidth is expected to go up sharply in the near future through various means, assured bandwidth is another matter. Greater bandwidth implies greater demands. Live classes and live office hours need their bandwidth continuously available.
If all else fails, the students can watch the archived lectures at a time that there is less demand on the network. In addition, to deal with online students that are behind a fire wall, we make the latest two lectures from each class also available for download via http.
The small video window is effective because of the use of prepared lecture notes transmitted separately at full size. When lecturing directly from the lecture notes, an electronic magnifying glass allows selected text under discussion to be magnified so that it becomes readable in the video window. Lecture notes are colorized to allow quick identification in the small video window. There is also a button on the live lecture browser screen that puts the student on the exact same lecture note page that the instructor is on. (This function is automatic for the archived lectures.)
An electronic whiteboard can be used to teach material not in the prepared notes. We use a drawing pad with a pre-school slate taped on it so that the instructor can see what she or he is writing. A small true whiteboard, as well as a document camera, are also available to the instructors, if they prefer them.
Since the web pages and the streaming media are independent systems, they back up each other. One instructor once taught an entire lecture through the whiteboard when the web server did not want to serve the lecture notes. Several very positive student responses were received in the feedback; however, this may have had much to do with the fact that the instructor went deliberately slow and covered noticeably less than he intended to.
There are help buttons on the live lecture screen that provide help with difficulties that can arise and their possible solution. They include help with the audio, the video, the chat box, and how to catch up with the instructor, if needed.
Since two-way video conferencing during lectures proved a distraction and unreliable, we substituted a chat box program. The chat box changes color whenever a student types in a question or remark, as a visual cue to the instructor. This ensures that the instructor will not readily miss the question while absorbed in teaching.
Besides the chat frame, we minimize distractions for the instructor further by having a T.A. present during the lecture. The T.A. manages the video to show the instructor, students asking questions, or the computer video screen as needed. The T.A. also watches for proper operation of all equipment. Before the lecture, the T.A. sets up all required hardware and software, which takes about 10 minutes. After the lecture, the T.A. links the lecture notes permanently to the archived video and sets up a web page for it. With practice, and using various custom software, this takes about 20 minutes.