Query formulation and Feed-back study for a Thesaurus based Information System

Abstract

Query formulation is an output activity just as indexing is an input activity. Query formulation techniques are discussed, with reference to the International Nuclear Information System (INIS), its thesaurus and its data base. The improvement of query by feed-back study is examined. Different techniques of evaluating the retrieval of documents and simple mathematical expressions to calculate recall ratio and pertinence ratio are given. The ranking of pertinency of documents and its utility is discussed.