In Table 4 we can observe the indirect comparison of our results with those of (Banerjee and Chua, 2014) and (Ren et al., 2014) obtained with a 10 fold cross validation experiment, and then, with a 5 fold cross validation in order to make a fair comparison with the results of (<cite>Ott et al., 2011</cite>) and (Feng and Hirst, 2013) .