The advantages of this approach include the fact that queries are easy to construct, terms can be weighted, and output can be ranked. The similarity between a document and a query can be readily compared and computed. What are the alternatives to the Boolean approach? Salton described a vector processing system in which the documents are described as term vectors or sets and queries are input in the same way.
) a document that contains all but one of the required terms is treated in the same way-i.e., not retrieved-as one that contains none of the required terms. On the other hand, in an AND search (A AND B AND C. ), a document containing only one of the terms is accorded the same weight as one that contains many or all of the search terms. Perhaps the most serious criticism of the Boolean approach, however, is that it sometimes produces results that are counter to those one would expect using intuitive reasoning.įor example, in an OR search (A OR B OR C. Among the negative aspects of the Boolean approach that Salton identified were: the difficulty of formulating a good Boolean query, the inability to limit the size of the output set, the fact that output cannot be ranked in any logical or useful order, and the inability to weigh the terms in either the query or the document. Cleverdon and reported in the October 1983 issue of LSN. In a presentation of recent research at ASIS, Gerard Salton of Cornell University continued the attack on Boolean search techniques begun by Cyril W.
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