Empathetic Dialogue Generation via Knowledge Enhancing and Emotion Dependency Modeling

Enabling the machines with empathetic abilities to provide context-consistent responses is crucial on both semantic and emotional levels. The task of empathetic dialogue generation is proposed to address this problem. However, two challenges still exist in this task: perceiving nuanced emotions implied in the dialogue context and modelling emotional dependencies. Lacking useful external knowledge makes it challenging to perceive implicit fine-grained emotions. Missing the emotional interactions among interlocutors also restricts the performance of empathetic dialogue generation. To address above challenges, we propose a knowledge-enhanced framework, named Know-EDG. We first enrich dialogue context by bunches of emotion-related concepts and construct a knowledge-enhanced context graph. Then we introduce a graph-aware Transformer encoder to learn graph's semantic and emotional representations, which are the prerequisites of the emotion identifier to predicate the target emotion signal. Finally, we propose an emotion-focused attention mechanism to exploit the emotional dependencies between dialogue context and target empathetic response. Conducted on a benchmark dataset, extensive experimental results show that our proposed framework outperforms state-of-the-art baselines in terms of automatic metrics and human evaluations.