At present, it requires many hours of processing for one hour of lecture. An archival Web lecture also needs advanced search capabilities. Whiteboard functionality, however, is hardly necessary because course developers can prepare all required graphics or animations in advance. A present a base-level Web lecture is a sequence of static slides with a separate audio or video narration file for each slide or video. Systems offering no more than the base-level features may survive on the market if they are well supported, inexpensive, reliable, or because customers do not demand more sophistication.
Authored synchronization allows line-level access to the material, but it is much more expensive.
Slides or sometimes lines, are indexed or annotated to allow keyword or full-text search. These features, often incorporating advanced elements of artificial intelligence, are not yet available in commercial systems. When such features are incorporated into several commercial systems, they define a new base level. This development in video processing, software tools, and bandwidth availability will make Web lectures an ever-increasing strategic part of the online curriculum. Peter Brusilovsky, Ph.D., has been involved in the benchmarking study and development of Web-based educational systems for several years.