4. An information classification device according to claim 1 , wherein the character information extracting means comprises extraction information storing means for storing extraction information to extract the character strings from the character information of the data, and extracts the character strings from the character information of the data based on the extraction information.
4. An information classification device according to claim 1 , wherein the character information extracting means comprises extraction information storing means for storing extraction information to extract the character strings from the character information of the data, and extracts the character strings from the character information of the data based on the extraction information. 5. An information classification device according to claim 4 , further comprising division criteria storing means for storing a predetermined division criterion, wherein: the character information extracting means divides a set of the character strings extracted based on the extraction information into a plurality of partial character string sets based on the predetermined division criterion; the labeling means replaces the character strings included in the partial character string sets with the label for each class; and the label appearance pattern estimating means receives, as an input, a label string obtained by the replacement of the partial character string set by the labeling means to estimate a label appearance pattern.