11. The method according to claim 10 , wherein the model based topic segmentation step outputs a segmentation confidence, representing the degree of certainty of segmentation of the text, to at least one interval obtained on segmentation of the text in association with the topic, the parameter estimation step, in the interval of a higher value of the segmentation confidence, estimating the parameter used in the change point detection topic segmentation step, using the result of segmentation by the model based topic segmentation step as training data.
16. The method according to claim 11 , wherein the model based topic segmentation step computes the segmentation confidence by a likelihood of the topic model or by an entropy of an a posteriori probability of the topic model for at least one interval obtained on segmentation of the text in association with the topic.