(1) Experimental Procedure

One of the documents is selected for the query sentences from the articles which belong to the same subject. The examination was conducted to find the other articles from 5,079 documents. Changing the query sentences, this procedure was repeated 90 times and average performances were evaluated.

In order to compare the results to the conventional method, experiments for W-VSM were also performed. In this case, "$tf \cdot idf$" was used to determine the dimension and the nouns were used for bases in the order of the value of "$tf \cdot idf$".