Information-based complexity; An overview

The author examines the following questions: Given specific information, what algorithm makes the best use of it, and is this algorithm simple and easy to implement? If information can be selected, what is the best strategy for doing so, and is this strategy adaptive (sequential)? How do the answers to the above questions change for noisy information? It is shown how the answers sometimes lead to sharp complexity bounds. Some generalizations concerning different error criteria, asymptotic setting, and random methods are briefly discussed.