1. An information processing apparatus comprising: an input unit configured to input, by a user, an annotation of at least one of an underline, a box, a character, a character string, a symbol, and a symbol string in a position on a document to be annotated by the user that identifies coverage of a certain portion of the document; a display configured to display both the document and the user inputted annotation concurrently on the document; a first memory to store a plurality of patterns each expressed in at least one of a character, a character string and a symbol, and for each a semantic class representing a type or meaning of information matching; a second memory to store intention estimation knowledge information for estimating an intention of the user organized by type of annotation and related semantic class of information; an annotation recognition unit configured to recognize a type of annotation input by the user and a coverage of the annotation in the displayed document; a semantic class analyzer to provide a semantic class for information matching a pattern in the coverage of the displayed document identified by the user-inputted annotation; an intention estimation unit configured to estimate an intention of the user based on the intention estimation knowledge information determined by the semantic class provided by the semantic class analyzer and the type of recognized annotation, wherein the intention of the user corresponds to an action the user intends to perform; an action selection unit configured to select the action intended by the user based on the intention estimated by the intention estimation unit; an execution unit configured to execute the action selected by the action selection unit by extracting at least one information item from the displayed document and creating an output including the one information item; and a display unit configured to display a view of the output created by the execution unit.