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)