Incomplete Utterance Rewriting by A Two-Phase Locate-and-Fill Regime

Rewriting incomplete and ambiguous utterances can improve dialogue models' understanding of the context and help them generate better results. However, the existing end-toend models will have the problem of too large search space, resulting in poor quality of rewriting results. We propose a 2-phase rewriting framework which first predicts the empty slots in the utterance that need to be completed, and then generate the part to be filled into each positions. Our framework is simple to implement, fast to run, and achieves the state-of-the-art results on several public rewriting datasets. A: I heard that J.K. Rowling's new book has been published. B: Great. I'm going to the bookstore in town.