Both statistical (Lample et al., 2018b;Artetxe et al., 2018b) and neural (Artetxe et al., 2018c;Lample et al., 2018a) MT approaches were proposed which are promising directions to overcome the data sparsity problem.
various issues of the approaches still have to be solved, e.g., better word reordering during translation or tuning system parame-ters.