Foundations of Probabilistic and Utility-Theoretic Indexing

One of the most perplexing problems of reformation retrieval has been the estabhshment of rational criteria for deciding what index terms or descriptors to assign to a unit of stored information for purposes of later retrieval Both probablhstJc and utlhty-theoretlc criteria have m the past been proposed for thts purpose. The present paper derives explicit decision rules of both kinds from a common conceptual and mathematical foundation The result IS a unified theory of indexing