Stanford University: Online Courses With Windows NT

• 06/24/1998

Stanford offers 15 of its graduate courses in engineering and computer science on the Web during each quarter, and approximately 1,500 students use Stanford Online to attend and gain credit for classes without ever stepping on campus. Instead, students who are enrolled in the classes can view a video version of the course on an ordinary computer with a connection to the Internet.

Here's how the process works: As a professor conducts a class, it is captured by cameras mounted in specially equipped classrooms. The signal is simultaneously transmitted to companies linked to Stanford's television network, put on videotape, and sent directly to Stanford Online.

The online staff members digitally capture the video feed as an AVI file and add materials such as slides used during the lecture. The video, audio and additional materials are all combined into one package and put onto a Windows NT server. Using VXtreme, a compression technology originally developed at Stanford, staff members can compress an hour-long video from 2 GB to 30 MB in about an hour. From start to finish, it takes about 3 hours to get a class on the Web, says Michael Rouan, Stanford's Online Manager.

With VXtreme, the classes are delivered to students through streaming video. While this solution means that Macintosh users are left out of the action, the upside is that users never have to download files. The bits and bytes that make up the video merely stream through a machine's cache and appear on the screen. "With streaming video, the image is never stored on the hard drive," Rouan explains.

With VXtreme compression technology, users watch the video at a relatively high rate of 10 frames per second. By comparison, film runs at 30 frames per second, and many other video-streaming technologies run at 5 frames per second. VXtreme compression technology enables Stanford to supply as many as 1,000 students with streaming video simultaneously.

For years, Stanford has broadcast classes live via microwave transmission to local corporations and other organizations in the Bay Area and Silicon Valley, but that solution requires students to have access to microwave facilities when the class is broadcast. The university can send videotapes of the classes to distance learners who cannot receive those microwave transmissions, but it takes time and effort to get the tapes from Stanford to students across the country in a timely manner. Since remote students are expected to meet the same deadlines as students living on campus, completing course work on time can be a problem for both students and teachers.

The online service changes all of that. While students need access to special equipment to watch the satellite broadcast, the Web is readily available to most professionals. And there are advantages to having classes stored on the Web that can't be offered by videotapes or satellite broadcasts. "Reviewing a course on videotape is nearly impossible," says Rouan. "With Stanford Online, you can go to a certain part of a class, because each course has keywords. If you're having problems with a certain theory, you can go right to the lectures on that theory." Students can also go back and view or search through old lectures at any time during the quarter.

In just more than a year of operation, the online classes are attracting about 750 users each quarter, or about half of the overall number of students who take classes through Stanford's distance learning program. And as Stanford expands the online service, that popularity will continue to grow. Stanford is planning to begin offering archived courses, so students can take courses even if they are not being offered that semester.