We also conjecture that the discrepancy between EMAIL and FORUM is probably due to the more heterogeneous nature of the FORUM data where anyone can post and reply while EMAIL (Enron or The improvement of less frequent tags is prominent, for example 25% for action motivator (AC), 40% for polite mechanism (P), and 15% for rhetorical question (QR) error rate reductions were achieved in FORUM data ( Figure 5(b)).
the semi-supervised learning method is more effective with small amounts of labeled data (i.e., less frequent annotations).