21. The computer-readable recording medium storing the program according to claim 20 , wherein the parameter estimation processing estimates a parameter used by the change point detection topic segmentation processing to segment the segmentation target interval, using the result of segmentation by the model based topic segmentation processing for a range of the segmentation target interval plus a preset range extended from the segmentation target interval of the text by the change point detection topic segmentation processing as training data.
26. The computer-readable recording medium storing the program according to claim 21 , wherein the segmentation target interval includes a plurality of intervals, the parameter estimation processing estimating a parameter used by the change point detection topic segmentation processing in segmenting the segmentation target interval into the intervals, using the result of segmentation by the model based topic segmentation processing for a range of the segmentation target interval plus a preset range extended from the segmentation target interval as training data, and the change point detection topic segmentation processing segmenting the segmentation target interval into the intervals, using a parameter estimated for the segmentation target interval by the parameter estimation processing.