Multi-turn response selection in retrieval-based chatbots with iterated attentive convolution matching network

Abstract

Building an intelligent chatbot with multi-turn dialogue ability is a major challenge, which requires understanding the multi-view semantic and dependency correlation among words, n-grams and sub-sequences. In this paper, we investigate selecting the proper response for a context through multi-grained representation and interactive matching. To construct hierarchical representation types of text segments, we propose a refined architecture which exclusively consists of gated dilated-convolution and self-attention. Compared with the recurrent-based sentence modeling methods, this architecture provides more flexibility and a speedup. The matching signals of each utterance-response pair are extracted by integrating the interactive information from different views. Then a turns-aware attention mechanism is utilized to aggregate the matching sequence, so as to identify important utterances and capture the implicit relationship of the whole context. Experiments on two large-scale public data sets show that our model significantly outperforms the state-of-the-art methods in terms of all metrics. We empirically provide a thorough ablation test, as well as the comparison of different representation and matching strategies, for a better insight into how each component affects the performance of the model.