Patent ID: 7039633

Claim:
A method for finding documents which relate to a portion of a temporal document, comprising: (a) in response to a signal of interest at a particular time during the temporal document, identifying a portion of the temporal document occurring during a time interval before said signal of interest; (b) selecting text associated with the portion of the temporal document identified, by reference to a database wherein is stored each term in text associated with the temporal document, together with a time in the temporal document at which the term occurs; (c) for a first term in the selected text, determining a first weight based on: a function W(t) associated with said time interval, and the time in the temporal document at which said first term occurs, wherein W(t) is equal for all times between t 1 before the signal of interest is given and t 2 before the signal is given, and decreases from t 1 until the time of the signal, and increase from a time t 3 before the signal is given to the time t 2 , and is zero for all other times; (d) identifying the related documents by use of information retrieval techniques as applied to said first term and said first weight.