  MINDS is a distributed system of cooperating query engines that customize,
document retrieval for each user in a dynamic environment. It improves its
performance and adapts to changing patterns of document distribution by
observing system-user interactions and modifying the appropriate certainty
factors, which act as search control parameters. It argued here that the
uncertainty management calculus must account for temporal precedence,
reliability of evidence, degree of support for a proposition, and saturation
effects. The calculus presented here possesses these features. Some results
obtained with this scheme are discussed.
