The classification results on the German play collection, the English article collection, and the French novel collection are presented in Figures 1, 2 and 3, respectively. The y-axis is the F1(macro)-score, and the x-axis shows the portion of words that are replaced or removed. The blue boxplots and the yellow boxplots represent the classification results, when the words in texts are replaced with POS-tags or removed, respectively. As the reference value, the classification results for the original data are also shown in the figures. The Welch’s t-test is also performed to determine the difference in classification results. The “ns” in the figures means non-significance.