1. A method for processing a document comprising a plurality of words to extract an answer from the document, the method using a plurality of signatures and a plurality of rules based on the signatures, the method comprising: establishing the plurality of signatures; establishing the plurality of rules, each rule including a name formed by concatenating the signatures included in the rule; a concept, the concept assignable to the combination of signatures included in the scope of the rule; parsing the plurality of words; assigning a signature to each of the plurality of words; assigning a window, the window including a parameter defining the number of signatures viewable at one time; moving the window if applicable, so that the window reveals signatures not viewable in its previous position; reading the signatures viewable in the window; creating a rule name by concatenating the read signatures; comparing the created rule name to the names of the plurality of rules; determining whether the created name matches any of the rule names; applying the matching rule to create a concept if a matching rule exists; and assigning the concept back into the window.