There are other studies in literature (e.g.
the idea of combining word embeddings and external knowledge to specialise them for a specific task has been actively explored in the last few years (Wang et al., 2014; Levy and 1 https://code.google.com/p/word2vec/ Goldberg, 2014;tang et al., 2014;Yu and Dredze, 2014;Wang et al., 2015;Pham et al., 2015;Liu et al., 2015), but all these studies extend the embeddings at word level.