Patent ID: 6876990

Claim:
A questionnaire analysis system comprising: means for inputting a questionnaire statement including free reply description in natural language; a network for transmitting a questionnaire reply statement, a database for accumulating said questionnaire reply statements transmitted through said network; and a text classification engine for reading out said questionnaire reply statements from said database and for learning a rule for classifying said questionnaire reply statement, wherein said text classification engine includes: morpheme analysis means for analyzing morphemes in all sentences in said questionnaire reply statement accumulated in said database; category-text designating means for designating a category and text; attribute selecting means for selecting attributes in plural questionnaire reply statements being read out from said database; rule learning means for learning said rule for expressing said correspondence of text and category on the basis of said words selected by attributes by said attribute selecting means; and rule output means for issuing said rule learned by said rule learning means, wherein said attribute selecting means computes a difference ΔSC(ω) between a stochastic complexity (SC) of a text set without consideration of appearance of a word and a stochastic complexity (SC) of a text set with consideration thereof, in each word ω appearing in said text, and then selects said difference ΔSC(ω) as an attribute when said difference ΔSC(ω) is larger than a threshold τ.