Han Li


Learning Slice-Aware Representations with Mixture of Attentions
Cheng Wang | Sungjin Lee | Sunghyun Park | Han Li | Young-Bum Kim | Ruhi Sarikaya
Findings of the Association for Computational Linguistics: ACL-IJCNLP 2021

A Scalable Framework for Learning From Implicit User Feedback to Improve Natural Language Understanding in Large-Scale Conversational AI Systems
Sunghyun Park | Han Li | Ameen Patel | Sidharth Mudgal | Sungjin Lee | Young-Bum Kim | Spyros Matsoukas | Ruhi Sarikaya
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing

Natural Language Understanding (NLU) is an established component within a conversational AI or digital assistant system, and it is responsible for producing semantic understanding of a user request. We propose a scalable and automatic approach for improving NLU in a large-scale conversational AI system by leveraging implicit user feedback, with an insight that user interaction data and dialog context have rich information embedded from which user satisfaction and intention can be inferred. In particular, we propose a domain-agnostic framework for curating new supervision data for improving NLU from live production traffic. With an extensive set of experiments, we show the results of applying the framework and improving NLU for a large-scale production system across 10 domains.


Handling Rare Entities for Neural Sequence Labeling
Yangming Li | Han Li | Kaisheng Yao | Xiaolong Li
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics

One great challenge in neural sequence labeling is the data sparsity problem for rare entity words and phrases. Most of test set entities appear only few times and are even unseen in training corpus, yielding large number of out-of-vocabulary (OOV) and low-frequency (LF) entities during evaluation. In this work, we propose approaches to address this problem. For OOV entities, we introduce local context reconstruction to implicitly incorporate contextual information into their representations. For LF entities, we present delexicalized entity identification to explicitly extract their frequency-agnostic and entity-type-specific representations. Extensive experiments on multiple benchmark datasets show that our model has significantly outperformed all previous methods and achieved new start-of-the-art results. Notably, our methods surpass the model fine-tuned on pre-trained language models without external resource.


Continuous Learning for Large-scale Personalized Domain Classification
Han Li | Jihwan Lee | Sidharth Mudgal | Ruhi Sarikaya | Young-Bum Kim
Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long and Short Papers)

Domain classification is the task to map spoken language utterances to one of the natural language understanding domains in intelligent personal digital assistants (IPDAs). This is observed in mainstream IPDAs in industry and third-party domains are developed to enhance the capability of the IPDAs. As more and more new domains are developed very frequently, how to continuously accommodate the new domains still remains challenging. Moreover, if one wants to use personalized information dynamically for better domain classification, it is infeasible to directly adopt existing continual learning approaches. In this paper, we propose CoNDA, a neural-based approach for continuous domain adaption with normalization and regularization. Unlike existing methods that often conduct full model parameter update, CoNDA only updates the necessary parameters in the model for the new domains. Empirical evaluation shows that CoNDA achieves high accuracy on both the accommodated new domains and the existing known domains for which input samples come with personal information, and outperforms the baselines by a large margin.

Detecting Customer Complaint Escalation with Recurrent Neural Networks and Manually-Engineered Features
Wei Yang | Luchen Tan | Chunwei Lu | Anqi Cui | Han Li | Xi Chen | Kun Xiong | Muzi Wang | Ming Li | Jian Pei | Jimmy Lin
Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 2 (Industry Papers)

Consumers dissatisfied with the normal dispute resolution process provided by an e-commerce company’s customer service agents have the option of escalating their complaints by filing grievances with a government authority. This paper tackles the challenge of monitoring ongoing text chat dialogues to identify cases where the customer expresses such an intent, providing triage and prioritization for a separate pool of specialized agents specially trained to handle more complex situations. We describe a hybrid model that tackles this challenge by integrating recurrent neural networks with manually-engineered features. Experiments show that both components are complementary and contribute to overall recall, outperforming competitive baselines. A trial online deployment of our model demonstrates its business value in improving customer service.


Random Walks on Context-Aware Relation Graphs for Ranking Social Tags
Han Li | Zhiyuan Liu | Maosong Sun
Proceedings of COLING 2012: Posters