Pengfei Hong


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CIDER: Commonsense Inference for Dialogue Explanation and Reasoning
Deepanway Ghosal | Pengfei Hong | Siqi Shen | Navonil Majumder | Rada Mihalcea | Soujanya Poria
Proceedings of the 22nd Annual Meeting of the Special Interest Group on Discourse and Dialogue

Commonsense inference to understand and explain human language is a fundamental research problem in natural language processing. Explaining human conversations poses a great challenge as it requires contextual understanding, planning, inference, and several aspects of reasoning including causal, temporal, and commonsense reasoning. In this work, we introduce CIDER – a manually curated dataset that contains dyadic dialogue explanations in the form of implicit and explicit knowledge triplets inferred using contextual commonsense inference. Extracting such rich explanations from conversations can be conducive to improving several downstream applications. The annotated triplets are categorized by the type of commonsense knowledge present (e.g., causal, conditional, temporal). We set up three different tasks conditioned on the annotated dataset: Dialogue-level Natural Language Inference, Span Extraction, and Multi-choice Span Selection. Baseline results obtained with transformer-based models reveal that the tasks are difficult, paving the way for promising future research. The dataset and the baseline implementations are publicly available at


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MIME: MIMicking Emotions for Empathetic Response Generation
Navonil Majumder | Pengfei Hong | Shanshan Peng | Jiankun Lu | Deepanway Ghosal | Alexander Gelbukh | Rada Mihalcea | Soujanya Poria
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)

Current approaches to empathetic response generation view the set of emotions expressed in the input text as a flat structure, where all the emotions are treated uniformly. We argue that empathetic responses often mimic the emotion of the user to a varying degree, depending on its positivity or negativity and content. We show that the consideration of these polarity-based emotion clusters and emotional mimicry results in improved empathy and contextual relevance of the response as compared to the state-of-the-art. Also, we introduce stochasticity into the emotion mixture that yields emotionally more varied empathetic responses than the previous work. We demonstrate the importance of these factors to empathetic response generation using both automatic- and human-based evaluations. The implementation of MIME is publicly available at