As e-learning becomes more common, Hiltz and Goodman present empirical evidence on designing and teaching effective online courses. The volume provides an overview of models and an assessment of what needs to happen next. The emphasis is on the text-based asynchronous use of networks (e-mail, the Web) to support student-to- student and also teacher-to-student communication and collaborative learning. The studies reviewed, however, also include courses that employ synchronous media via the Net—such as text or audio chat and videoconferencing—and compare face-to-face, synchronous, and asynchronous learning processes