1. weighted search 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 documents 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].
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