Part I reviewed the major theories of learning and instruction which have influenced the design of recent computer-based systems to support education and training. Part II outlines the systems developed on the basis of these theories. Successful systems are limited currently to classes of learning task which are well structured. Argues that less well-structured tasks demand a different approach to training and are best served by technology designed to support collaborative learning in small groups. Outlines some practical limits on the creation and exploitation of technology. Discusses implications for future developments of technological aids to training and training research.