Xiang Gao


2021

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NICE: Neural Image Commenting with Empathy
Kezhen Chen | Qiuyuan Huang | Daniel McDuff | Xiang Gao | Hamid Palangi | Jianfeng Wang | Kenneth Forbus | Jianfeng Gao
Findings of the Association for Computational Linguistics: EMNLP 2021

Emotion and empathy are examples of human qualities lacking in many human-machine interactions. The goal of our work is to generate engaging dialogue grounded in a user-shared image with increased emotion and empathy while minimizing socially inappropriate or offensive outputs. We release the Neural Image Commenting with Empathy (NICE) dataset consisting of almost two million images and the corresponding human-generated comments, a set of human annotations, and baseline performance on a range of models. In-stead of relying on manually labeled emotions, we also use automatically generated linguistic representations as a source of weakly supervised labels. Based on these annotations, we define two different tasks for the NICE dataset. Then, we propose a novel pre-training model - Modeling Affect Generation for Image Comments (MAGIC) - which aims to generate comments for images, conditioned on linguistic representations that capture style and affect, and to help generate more empathetic, emotional, engaging and socially appropriate comments. Using this model we achieve state-of-the-art performance on one of our NICE tasks. The experiments show that the approach can generate more human-like and engaging image comments.

2020

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Dialogue Response Ranking Training with Large-Scale Human Feedback Data
Xiang Gao | Yizhe Zhang | Michel Galley | Chris Brockett | Bill Dolan
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)

Existing open-domain dialog models are generally trained to minimize the perplexity of target human responses. However, some human replies are more engaging than others, spawning more followup interactions. Current conversational models are increasingly capable of producing turns that are context-relevant, but in order to produce compelling agents, these models need to be able to predict and optimize for turns that are genuinely engaging. We leverage social media feedback data (number of replies and upvotes) to build a large-scale training dataset for feedback prediction. To alleviate possible distortion between the feedback and engagingness, we convert the ranking problem to a comparison of response pairs which involve few confounding factors. We trained DialogRPT, a set of GPT-2 based models on 133M pairs of human feedback data and the resulting ranker outperformed several baselines. Particularly, our ranker outperforms the conventional dialog perplexity baseline with a large margin on predicting Reddit feedback. We finally combine the feedback prediction models and a human-like scoring model to rank the machine-generated dialog responses. Crowd-sourced human evaluation shows that our ranking method correlates better with real human preferences than baseline models.

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Optimus: Organizing Sentences via Pre-trained Modeling of a Latent Space
Chunyuan Li | Xiang Gao | Yuan Li | Baolin Peng | Xiujun Li | Yizhe Zhang | Jianfeng Gao
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)

When trained effectively, the Variational Autoencoder (VAE) can be both a powerful generative model and an effective representation learning framework for natural language. In this paper, we propose the first large-scale language VAE model Optimus (Organizing sentences via Pre-Trained Modeling of a Universal Space). A universal latent embedding space for sentences is first pre-trained on large text corpus, and then fine-tuned for various language generation and understanding tasks. Compared with GPT-2, Optimus enables guided language generation from an abstract level using the latent vectors. Compared with BERT, Optimus can generalize better on low-resource language understanding tasks due to the smooth latent space structure. Extensive experimental results on a wide range of language tasks demonstrate the effectiveness of Optimus. It achieves new state-of-the-art on VAE language modeling benchmarks.

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MixingBoard: a Knowledgeable Stylized Integrated Text Generation Platform
Xiang Gao | Michel Galley | Bill Dolan
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics: System Demonstrations

We present MixingBoard, a platform for quickly building demos with a focus on knowledge grounded stylized text generation. We unify existing text generation algorithms in a shared codebase and further adapt earlier algorithms for constrained generation. To borrow advantages from different models, we implement strategies for cross-model integration, from the token probability level to the latent space level. An interface to external knowledge is provided via a module that retrieves, on-the-fly, relevant knowledge from passages on the web or a document collection. A user interface for local development, remote webpage access, and a RESTful API are provided to make it simple for users to build their own demos.

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DIALOGPT : Large-Scale Generative Pre-training for Conversational Response Generation
Yizhe Zhang | Siqi Sun | Michel Galley | Yen-Chun Chen | Chris Brockett | Xiang Gao | Jianfeng Gao | Jingjing Liu | Bill Dolan
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics: System Demonstrations

We present a large, tunable neural conversational response generation model, DIALOGPT (dialogue generative pre-trained transformer). Trained on 147M conversation-like exchanges extracted from Reddit comment chains over a period spanning from 2005 through 2017, DialoGPT extends the Hugging Face PyTorch transformer to attain a performance close to human both in terms of automatic and human evaluation in single-turn dialogue settings. We show that conversational systems that leverage DialoGPT generate more relevant, contentful and context-consistent responses than strong baseline systems. The pre-trained model and training pipeline are publicly released to facilitate research into neural response generation and the development of more intelligent open-domain dialogue systems.

2019

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Structuring Latent Spaces for Stylized Response Generation
Xiang Gao | Yizhe Zhang | Sungjin Lee | Michel Galley | Chris Brockett | Jianfeng Gao | Bill Dolan
Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP)

Generating responses in a targeted style is a useful yet challenging task, especially in the absence of parallel data. With limited data, existing methods tend to generate responses that are either less stylized or less context-relevant. We propose StyleFusion, which bridges conversation modeling and non-parallel style transfer by sharing a structured latent space. This structure allows the system to generate stylized relevant responses by sampling in the neighborhood of the conversation model prediction, and continuously control the style level. We demonstrate this method using dialogues from Reddit data and two sets of sentences with distinct styles (arXiv and Sherlock Holmes novels). Automatic and human evaluation show that, without sacrificing appropriateness, the system generates responses of the targeted style and outperforms competitive baselines.

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Jointly Optimizing Diversity and Relevance in Neural Response Generation
Xiang Gao | Sungjin Lee | Yizhe Zhang | Chris Brockett | Michel Galley | Jianfeng Gao | Bill Dolan
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)

Although recent neural conversation models have shown great potential, they often generate bland and generic responses. While various approaches have been explored to diversify the output of the conversation model, the improvement often comes at the cost of decreased relevance. In this paper, we propose a SpaceFusion model to jointly optimize diversity and relevance that essentially fuses the latent space of a sequence-to-sequence model and that of an autoencoder model by leveraging novel regularization terms. As a result, our approach induces a latent space in which the distance and direction from the predicted response vector roughly match the relevance and diversity, respectively. This property also lends itself well to an intuitive visualization of the latent space. Both automatic and human evaluation results demonstrate that the proposed approach brings significant improvement compared to strong baselines in both diversity and relevance.

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Conversing by Reading: Contentful Neural Conversation with On-demand Machine Reading
Lianhui Qin | Michel Galley | Chris Brockett | Xiaodong Liu | Xiang Gao | Bill Dolan | Yejin Choi | Jianfeng Gao
Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics

Although neural conversational models are effective in learning how to produce fluent responses, their primary challenge lies in knowing what to say to make the conversation contentful and non-vacuous. We present a new end-to-end approach to contentful neural conversation that jointly models response generation and on-demand machine reading. The key idea is to provide the conversation model with relevant long-form text on the fly as a source of external knowledge. The model performs QA-style reading comprehension on this text in response to each conversational turn, thereby allowing for more focused integration of external knowledge than has been possible in prior approaches. To support further research on knowledge-grounded conversation, we introduce a new large-scale conversation dataset grounded in external web pages (2.8M turns, 7.4M sentences of grounding). Both human evaluation and automated metrics show that our approach results in more contentful responses compared to a variety of previous methods, improving both the informativeness and diversity of generated output.

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Microsoft Icecaps: An Open-Source Toolkit for Conversation Modeling
Vighnesh Leonardo Shiv | Chris Quirk | Anshuman Suri | Xiang Gao | Khuram Shahid | Nithya Govindarajan | Yizhe Zhang | Jianfeng Gao | Michel Galley | Chris Brockett | Tulasi Menon | Bill Dolan
Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics: System Demonstrations

The Intelligent Conversation Engine: Code and Pre-trained Systems (Microsoft Icecaps) is an upcoming open-source natural language processing repository. Icecaps wraps TensorFlow functionality in a modular component-based architecture, presenting an intuitive and flexible paradigm for constructing sophisticated learning setups. Capabilities include multitask learning between models with shared parameters, upgraded language model decoding features, a range of built-in architectures, and a user-friendly data processing pipeline. The system is targeted toward conversational tasks, exploring diverse response generation, coherence, and knowledge grounding. Icecaps also provides pre-trained conversational models that can be either used directly or loaded for fine-tuning or bootstrapping other models; these models power an online demo of our framework.

2010

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Exploiting Rich Features for Detecting Hedges and their Scope
Xinxin Li | Jianping Shen | Xiang Gao | Xuan Wang
Proceedings of the Fourteenth Conference on Computational Natural Language Learning – Shared Task