Hypermedia technology needs a creative approach from the outset in the design of software to facilitate human thinking and learning. This book opens a discussion of the potential of hypermedia and related approaches to provide open exploratory learning environments. The papers in the book are based on contributions to a NATO Advanced Research Workshop held in July1990 and are grouped into six sections: - Semantic networking as cognitive tools, - Expert systems as cognitive tools, - Hypertext as cognitive tools, - Collaborative communication tools, - Microworlds: context-dependent cognitive tools, - Implementing cognitive tools. The book will be valuable for those who design, implement and evaluate learning