15. A computer program product having a non-transitory computer readable medium tangibly embodying computer readable instructions which, when executed, cause a computer to carry out the steps of a method for extracting predicate expressions representing defects from text data related to use of products, the method comprising: storing in a first predicate modifying expression storage module, as predicate modifying expressions for detecting defect expressions, at least one of predicate modifying expressions representing suddenness and predicate modifying expressions representing repeatability; detecting, in said text data, expressions matching each of the said stored predicate modifying expressions for detecting defect expressions and extracting, as a candidate for a predicate expression representing a defect, a predicate expression occurring in a neighborhood of each of the said detected expressions matching each of the said stored predicate modifying expressions for detecting defect expressions in said text data; storing in a second predicate modifying expression storage module, as predicate modifying expressions for detecting normality expressions, predicate modifying expressions representing normality; detecting, in said text data, expressions matching each of the said stored predicate modifying expressions for detecting normality expressions and extracting, as a predicate expression representing normality, a predicate expression occurring in a neighborhood of each of the said detected expressions matching each of the said stored predicate modifying expressions for detecting normality expressions in said text data; and acquiring, as said predicate expressions representing defects, predicate expressions remaining after said extracted predicate expressions are removed from a list of said predicate expressions extracted as said candidates for said predicate expressions representing defects.
15. A computer program product having a non-transitory computer readable medium tangibly embodying computer readable instructions which, when executed, cause a computer to carry out the steps of a method for extracting predicate expressions representing defects from text data related to use of products, the method comprising: storing in a first predicate modifying expression storage module, as predicate modifying expressions for detecting defect expressions, at least one of predicate modifying expressions representing suddenness and predicate modifying expressions representing repeatability; detecting, in said text data, expressions matching each of the said stored predicate modifying expressions for detecting defect expressions and extracting, as a candidate for a predicate expression representing a defect, a predicate expression occurring in a neighborhood of each of the said detected expressions matching each of the said stored predicate modifying expressions for detecting defect expressions in said text data; storing in a second predicate modifying expression storage module, as predicate modifying expressions for detecting normality expressions, predicate modifying expressions representing normality; detecting, in said text data, expressions matching each of the said stored predicate modifying expressions for detecting normality expressions and extracting, as a predicate expression representing normality, a predicate expression occurring in a neighborhood of each of the said detected expressions matching each of the said stored predicate modifying expressions for detecting normality expressions in said text data; and acquiring, as said predicate expressions representing defects, predicate expressions remaining after said extracted predicate expressions are removed from a list of said predicate expressions extracted as said candidates for said predicate expressions representing defects. 19. The computer program product according to claim 15 , further comprising computer readable program code configured to perform the steps of: extracting, from said text data, predicate modifying expressions co-occurring with a predicate expression representing a specific defect; and registering said predicate modifying expressions in said first predicate modifying expression storage module.