Generating Diverse Conversation Responses by Creating and Ranking Multiple Candidates

•This paper introduces our systems built for Track 2 of DSTC7.•Our work promotes the diversity of conversation response generation by two steps.•(1) Create multiple responses for an input context together with its textual facts.•(2) Rank and return the best response using a topic coherence discrimination model.•The effectiveness of our methods are confirmed by online and offline evaluations.