Analyzes the use of weights to denote a query representation and/or the indexing of a document as a generalization of a Boolean retrieval system. Criteria are given for the functions used to evaluate the relevance of the records to a specific query and a new evaluation approach is suggested. (CWM)

Presents a dynamic model of user behavior when scanning an information storage and retrieval system output list, compares rules for determining the user's optimum stopping point, presents an algorithm for implementing the Bayesian model, and discusses implications for retrieval system design. Provided are 13 figures and 15 references. (Author/RBF)