This article describes a research project in the area of cooperative telelearning. It summarizes the characteristics and results of a groupware-supported international teleseminar with 14 virtual student groups. On the basis of this field research and a theoretical model, the requirements and advantages of telepresence on effective and efficient learning are considered empirically. Thereafter, the article discusses additional determinants of learning productivity to explain the role of information and communication technology in the field of telelearning. In the field study, a generally positive effect of video communication on the perceived grade of telepresence was found, but no direct effect of telepresence on learning success could be traced back.