30. The non-transitory computer-readable storage medium according to claim 29 , the software program further comprising instructions that direct the computer to execute the step of (d) using a dictionary having registered therein a plurality of characteristic expressions and the respective classes of the plurality of characteristic expressions to compare the plurality of characteristic expressions registered in the dictionary with the text data, identifying the locations of occurrence where any of the plurality of characteristic expressions from the text data appear, and creating annotation information that identifies the position of the locations of occurrence and the classes of the characteristic expressions that appear.
31. The non-transitory computer-readable storage medium according to claim 30 , the software program further comprising instructions that direct the computer to execute the steps of: (e) learning characteristic expression extraction rules used to extract the characteristic expressions using the training data generated in Step (b), and (d) extracting characteristic expressions from a corpus containing a plurality of documents using extraction rules learned in Step (e) and adding and registering characteristic expressions that meet a preset condition among the extracted characteristic expressions, along with the class information that identifies their classes, in the dictionary.