Teleconferencing: is video valuable or is audio adequate?

Many telephone companies and administrations are developing audiovisual teleconference systems; by comparison audiographic systems are receiving attention almost exclusively from user organizations. The authors argue that although teleconferencing has had mixed success, with some installations being used often and judged successful while others are not, the existence of a visual channel showing the participants does not seem necessary. Many other factors likely to contribute to success are identified, which, as yet, have received little attention. It is recommended that they be studied through carefully monitored field trials.