Assuming that we have two spaces, the semantics space X and the natural language space Y, given n data pairs {(x i , y i )} n i=1 , the goal of NLG is to generate corresponding utterances based on given semantics.
table 1: the NLU performance reported on micro-F1 and the NLG performance reported on BLEU, ROUGE-1, ROUGE-2, and ROUGE-L of models (%).