ORmation science> A search based on frequencies of the search terms in the documents being searched. Weighted search is often used by search engines. It produces a numerical scORe fOR each possible document. A document' s scORe depends on the frequency of each search term in that document compared with the overall frequency of that term in the entire cORpus of documents. A common approach is called tf.idf which stands fOR term frequency * inverse document frequency. Term frequency means "the mORe often a term occurs in a document, the mORe impORtant it is in describing that document." http://ciir.cs.umass.edu/cmpsci646/ir4/tsld034.htm Inverse document frequency means the mORe documents a term appears in, the less impORtant the term is. A simple weighted search is just a list of search terms, fOR example: car automobile Weighted search is often contrasted with boolean search. It is possible to have a search that syntactically is a boolean search but which also does a weighted search. See also query expansion. FOR a detailed technical discussion see Chapter 5, "Search Strategies", in the reference below. [{"InfORmation Retrieval", C. J. van Rijsbergen, (http://www.dcs.gla.ac.uk/Keith/Chapter.5/Ch.5.html)}]. (1999-08-28)