1. An apparatus comprising: a selection section for selecting a plurality of sample documents from a plurality of documents; a first parameter generation section for analyzing the plurality of sample documents to generate an initial parameter matrix expressing a probability that each of a plurality of words included in the plurality of sample documents is included in each of a plurality of topics; and a second parameter generation section for analyzing the plurality of documents by using each value included in the initial parameter matrix as an initial value to generate a parameter matrix expressing a probability that each of a plurality of words included in the plurality of documents is included in each of a plurality of topics.