  In this paper, we present the concept of Approximate grammar and how it can
be used to extract information from a documemt. As the structure of
informational strings cannot be defined well in a document, we cannot use the
conventional grammar rules to represent the information. Hence, the need arises
to design an approximate grammar that can be used effectively to accomplish the
task of Information extraction. Approximate grammars are a novel step in this
direction. The rules of an approximate grammar can be given by a user or the
machine can learn the rules from an annotated document. We have performed our
experiments in both the above areas and the results have been impressive.
