When the size of paired data is small, the basic Seq2Seq model tends to generate more generic responses.
different from existing work, we assume that n is small (e.g., a few hundred thousands) and further assume that there is another set with T i a piece of plain text sharing the same characteristics with {Y i } n i=1 (e.g., both are questions) and N > n. Our goal is to learn a generation probability P (Y |X) with both d P and d U .