“…• For experiments, we have collected 5 data sets (instead of 2 Vietnamese data sets as in [13]). These data sets represent for 3 languages (English, Turkey, and Vietnamese) and have multi-classes (2, 4, 6, 9, and 10 classes as presented in Table 1) • In this work, since the topic classes are imbalanced, we have used AUC (Area Under the ROC Curve) as a metric for comparison.…”