This 1998 book covers the twin themes of computational complexity and information.The twin themes of of computational complexity and information pervade this book. Information-based complexity is used to illustrate a variety of topics, including breaking the curse of dimension, complexity of path integration, solvability of ill-posed problems, the value of information in computation, assigning values to mathematical hypotheses, and new, improved methods for mathematical finance.The style is inf ormal, and the goals are exposition, insight and motivation. As the first introductory book on the subject it will invaluable as a guide to the area.The twin themes of of computational complexity and information pervade this book. Information-based complexity is used to illustrate a variety of topics, including breaking the curse of dimension, complexity of path integration, solvability of ill-posed problems, the value of information in computation, assigning values to mathematical hypotheses, and new, improved methods for mathematical finance.The style is inf ormal, and the goals are exposition, insight and motivation. As the first introductory book on the subject it will invaluable as a guide to the area.The twin themes of computational complexity and information pervade this book. It starts with an introduction to information-based complexity, that is, the computational complexity of continuous mathematical models. It then moves to a variety of topics, including breaking the curse of dimensionality, complexity of path integration, solvability of ill-posed problems, value of information in computation, assigning values to mathematical hypotheses, and mathematical finance. The style is informal, and the goal is motivation and insight. Precise statements and proofs can be found in the monographs and papers included in the comprehensive bibliography. The book will be essential reading for researchers in the many disciplines influenced by the computational complexity of continlă+