Combining SMT and NMT Back-Translated Data for Efficient NMT
Table 2: Performance of models built with increasing sizes of authentic set (first column) and different synthetic datasets (last four columns). +1M, +2M and +3M indicate the amount of sentences added to the base set (1M authentic sentences).
['1M lines', 'BLEU↑', '1M  [ITALIC] base. 23.40', '-', '-', '-', '-']
The sub-tables indicate the size of the data used for building the models (from 1M to 4M lines). In each column it is indicated whether base has been augmented with the auth, SMTsynth, NMTsynth, hybrNMTSMT, or fullhybrNMTSMT data set.