11. A non-transitory computer readable medium configured to store a text mining program configured to cause a computer to execute text mining processing, said computer is connected to a text set storage unit configured to store a plurality of text obtained by forming a plurality of non-text data into the plurality of text and a reliability storage unit configured to store an all-class reliability for each of the plurality of text stored in said text set storage unit, said all-class reliability being derived from the formation of said plurality of non-text data into said plurality of text, said text mining processing including: a text mining processing of searching, the plurality of text for a plurality of text of a same class, where said plurality of text of the same class has a characteristic the same as the plurality of text stored in said text set storage unit; and a text selection processing of reading, when said plurality of texts of the same class are searched, a same-class reliability of each of said plurality of text of the same class from said reliability storage unit, and selecting a part of said plurality of text of the same class from the plurality of text of the same class based on the same-class reliability, wherein said text selection processing includes: a degree of assurance generation processing of generating, for each of said plurality of text of the same class, a degree of assurance indicative of a degree of correlation between said plurality of text of the same class and said plurality of non-text data based on the same-class reliability of said plurality of text of the same class; and a selection processing of selecting a portion of said plurality of text of the same class having the highest degree of assurance as said part of said plurality of text of the same class from among said plurality of text of the same class.
11. A non-transitory computer readable medium configured to store a text mining program configured to cause a computer to execute text mining processing, said computer is connected to a text set storage unit configured to store a plurality of text obtained by forming a plurality of non-text data into the plurality of text and a reliability storage unit configured to store an all-class reliability for each of the plurality of text stored in said text set storage unit, said all-class reliability being derived from the formation of said plurality of non-text data into said plurality of text, said text mining processing including: a text mining processing of searching, the plurality of text for a plurality of text of a same class, where said plurality of text of the same class has a characteristic the same as the plurality of text stored in said text set storage unit; and a text selection processing of reading, when said plurality of texts of the same class are searched, a same-class reliability of each of said plurality of text of the same class from said reliability storage unit, and selecting a part of said plurality of text of the same class from the plurality of text of the same class based on the same-class reliability, wherein said text selection processing includes: a degree of assurance generation processing of generating, for each of said plurality of text of the same class, a degree of assurance indicative of a degree of correlation between said plurality of text of the same class and said plurality of non-text data based on the same-class reliability of said plurality of text of the same class; and a selection processing of selecting a portion of said plurality of text of the same class having the highest degree of assurance as said part of said plurality of text of the same class from among said plurality of text of the same class. 13. The non-transitory computer readable medium configured to store the text mining program according to claim 11 , wherein in said text mining processing, a word is used as said characteristic, and in said degree of assurance generation processing, for each of said plurality of text of the same class, said same-class reliability of said word used as said characteristic and a proximate-word reliability of a word in proximity to the word used as said characteristic are read from said reliability storage unit to generate, for each of said plurality of text of the same class, said degree of assurance based on said same-class reliability of the word used as said characteristic and said proximate-word reliability of the word in proximity to the word used as said characteristic.