Patent ID: 7730050

Claim:
An information retrieval apparatus comprising: a display configured to display document information; an input unit configured to receive user input to add additional information to the displayed document information at an input location; a first storage configured to store mark symbol information specifying a particular symbol used for marking; a detector configured to detect the additional information from the input unit, and to decide whether or not the input additional information is identical to or similar to the mark symbol information stored in the first storage; a specification unit configured to specify a range of the input location based on a predetermined user selection input received by the input unit; a second storage configured to store the input additional information which is identical to or similar to the mark symbol information, and to associate the mark symbol information with a portion of the displayed document information within the range; and a retrieval unit configured to retrieve the portion of the displayed document information within the range from the second storage using the mark symbol information as a search key, wherein the retrieved portion of the displayed document information is displayed on the display.