2. The text segmentation apparatus according to claim 1 , wherein the model base topic segmentation section outputs a segmentation confidence representing the degree of certainty of the segmentation of the text to at least one interval obtained on segmentation of the text in association with a topic, the parameter estimation section estimating the parameter used by the change point detection topic segmentation section, in an interval of a higher segmentation confidence, using the result of segmentation by the model base topic segmentation section as training data.
2. The text segmentation apparatus according to claim 1 , wherein the model base topic segmentation section outputs a segmentation confidence representing the degree of certainty of the segmentation of the text to at least one interval obtained on segmentation of the text in association with a topic, the parameter estimation section estimating the parameter used by the change point detection topic segmentation section, in an interval of a higher segmentation confidence, using the result of segmentation by the model base topic segmentation section as training data. 7. The text segmentation apparatus according to claim 2 , wherein the model base topic segmentation section computes the segmentation confidence for at least one interval obtained on segmenting the text in association with the topic by a likelihood of the topic model or an entropy of an a posteriori probability of the topic model.