Text search system

Claim 3

A method according to claim 1 wherein said function of the equivalence values in step (ii) includes a weighting factor based upon positions in said document of words in said target sequence.

Claim 4

A method according to claim 1 wherein said matching criteria include the ordering of a sequence of words in the library document with respect to the sequence of query words.

Claim 5

A method according to claim 1 wherein said matching criteria include the completeness of a match between a sequence of words in the library document and the sequence of query words.

Claim 6

A method according to claim 1 wherein said matching criteria include the span of a sequence of words in the library document that matches the sequence of query words.

Claim 7

A method according to claim 1 comprising the additional step of preselecting a subset of library documents and computing the relevancy factors only for said subset of library documents, and ranking library documents in order of their respective relevance factors.

Claim 8

A method according to claim 6 wherein said relevance factor of a library document is the similarity value of a target sequence having the highest similarity value.

Claim 9

A method according to claim 7, wherein a similarity value S xyz is being evaluated according to the equation: where L1 represents the target sequence; L2 represents the sequence of query words; x represents said ordering matching criterion; y represents said completeness matching criterion; z represents said span matching criterion; and d(f xz ) = m if y =1, and = max (m, spread of f xz ) if y=2.

Claim 10

A document retrieval system storing more than one library document, an apparatus for retrieving library documents matching the content of a sequence of query words, comprising: (a) means for storing a set of equivalent words for each of the query words, each of said equivalent words being stored with a corresponding word equivalence value; and (b) means coupled to said storage means for computing a relevance factor for a library document, comprising: (i) first means for receiving a set of matching criteria; (ii) second means coupled to said first means for locating target sequences of words in a library document that match the sequence of query words, and equivalence thereof, according to said matching criteria; (iii) third means coupled to said second means for evaluating similarity values of said target sequences of words, each similarity value being evaluated as a function of the equivalence values of words included in the corresponding target sequence; and (iv) fourth means receiving said similarity values for computing said relevance factor.

Claim 11

A document retrieval system storing more than one library document, an apparatus for retrieving library documents matching the content of a sequence of query words, comprising: (a) means for storing a set of equivalent words for each of the query words, each of said equivalent words being stored with a corresponding word equivalence value; and (b) means coupled to said storage means for computing a relevance factor for a library document, comprising: (i) first means for receiving a set of matching criteria; (ii) second means coupled to said first means for locating target sequences of words in a library document that match the sequence of query words, and equivalence thereof, according to said matching criteria; (iii) third means coupled to said second means for evaluating similarity values of said target sequences of words, each similarity value being evaluated as a function of the equivalence values of words included in the corresponding target sequence; and (iv) fourth means receiving said similarity values for computing said relevance factor.

Claim 12

Apparatus as in claim 9 wherein said function is said third means includes a weighting factor based upon positions in said document of words in said target sequence.