The purpose of this book is to stimulate reflection on the different issues concerning the design, development and implementation of interactive multimedia learning systems. Multimedia, hypermedia, and interactive systemsmore generally need to be examined in terms of underlying cognitive processes, interface characteristics, and theoretical principles regarding learner control of instruction. This book is based on a NATO Advanced Research Workshop held in Quebec in 1991. The papers in the book present a critical analysis of the multimedia design concept that reveal it to be still immature, sometimes ambiguous, and even confusing. Within this contexta variety of different design dimensions are considered, such as those of interfaces, procedures, content, control, and advisory processes. A central requirement is to define the interactivity concept, both to enable the learner and the system to collaborate through communication and to direct this communication in order to stimulate effective learning. Proposals made in the book include adaptive interfaces, interactive transactions, intelligent strategies, knowledge representation, and student modeling.