个性化对话的产生对于自然和人类的谈话至关重要。通常，个性化对话生成模型涉及对对话历史的生成响应以及对话者的角色/人格的表示。由于获得每个对话者的人格/人格表征是不切实际的，最近的作品已经探讨了通过将模型与对应于给定的人格对应的对话示例的模型来产生个性化对话的可能性。然而，在实际实现中，足够数量的相应对话示例也很少可用。因此，在本文中，我们提出了一种能够在没有任何人格/人格信息或任何相应的对话示例的情况下产生个性化对话的双潜变量发生器（DLVGEN）。与现有工作不同，DLVGEN模拟潜在响应的潜在分布以及代理商的潜在角色的潜在分布。在推理期间，从两个分布中采样潜在变量并进入解码器。经验结果表明，DLVGEN能够产生各种反应，精确地纳入代理人的角色。

当前的个性化对话中的作品主要有助于代理人表现出一致的个性并推动更有用的回应。但是，我们发现大多数以前模型的生成的响应往往是以自我为中心的，对话中的用户几乎不关心。此外，我们认为类似人类的对话基本上是基于推断另一方角色的信息而构建的。由此激励，我们通过检测隐性用户角色提出了一种新颖的个性化对话生成器。因为很难为每个用户收集大量详细的角色，所以我们试图对用户的潜在角色及其从对话历史记录进行建模，而没有外部知识。使用条件变异推断对感知和推子变量进行了构想。两个潜在变量模拟了人们意识到彼此角色并在对话中产生相应表达的过程。最后，提出了后歧视的正规化以增强训练程序。实证研究表明，与最先进的方法相比，我们的方法更关心用户的角色，并在整个评估中实现了相当大的推动力。

Conditional variational models, using either continuous or discrete latent variables, are powerful for open-domain dialogue response generation. However, previous works show that continuous latent variables tend to reduce the coherence of generated responses. In this paper, we also found that discrete latent variables have difficulty capturing more diverse expressions. To tackle these problems, we combine the merits of both continuous and discrete latent variables and propose a Hybrid Latent Variable (HLV) method. Specifically, HLV constrains the global semantics of responses through discrete latent variables and enriches responses with continuous latent variables. Thus, we diversify the generated responses while maintaining relevance and coherence. In addition, we propose Conditional Hybrid Variational Transformer (CHVT) to construct and to utilize HLV with transformers for dialogue generation. Through fine-grained symbolic-level semantic information and additive Gaussian mixing, we construct the distribution of continuous variables, prompting the generation of diverse expressions. Meanwhile, to maintain the relevance and coherence, the discrete latent variable is optimized by self-separation training. Experimental results on two dialogue generation datasets (DailyDialog and Opensubtitles) show that CHVT is superior to traditional transformer-based variational mechanism w.r.t. diversity, relevance and coherence metrics. Moreover, we also demonstrate the benefit of applying HLV to fine-tuning two pre-trained dialogue models (PLATO and BART-base).

个性化对话代理对于对话系统非常重要，以产生更具体，一致，并从事和吸引力的反应。然而，大多数当前对话的个性化方法依赖于推理期间的明确人物描述，严重限制其应用。在本文中，我们提出了一种新颖的方法，该方法将根据对话历史来预测人物信息，以个性化对话代理而不依赖于推理期间的任何明确的人格描述。 Personachat数据集上的实验结果表明，当在对话剂的预测轮廓上调节（即“自身角色”）时，所提出的方法可以提高所产生的响应的一致性，并在预测的角色调节时改善所产生的响应的接合对话伙伴（即“他们的角色”）。我们还发现培训的角色预测模型可以成功转移到其他数据集，并帮助生成更相关的响应。

尽管条件变异自动编码器（CVAE）模型比传统的SEQ2SEQ模型可以产生更多的多样化响应，但响应通常与输入词的相关性低或与问题不合逻辑。进行因果分析以研究背后的原因，并提供了一种寻找调解人并减轻对话中混杂偏见的方法。具体而言，我们建议预测调解人，以保留相关信息，并自动将调解人纳入生成过程中。此外，动态主题图指导条件变异自动编码器（TGG-CVAE）模型用于补充语义空间并减少响应中的混杂偏置。广泛的实验表明，所提出的模型能够产生相关和信息性的响应，并且在自动指标和人类评估方面优于最先进的响应。

以一致的性格赋予聊天机器人对于代理商提供类似人类互动的作用至关重要。但是，现有的个性化方法通常会根据用文本描述描绘的静态预定义角色产生响应，这可能严重限制了人类和聊天机器人的互动性，尤其是当代理人需要回答预定义角色中排除的查询时，这是如此 - 被称为预先定义的角色问题（以简单性为OOP）。为了减轻问题，在本文中，我们提出了一个新颖的检索到预测范式，该范式由两个子组件组成，即（1）角色检索模型（PRM），它根据自然语言推论从全球收藏中检索角色（ NLI）模型，推断的角色与预定义的角色一致； （2）后验变压器（PS-Transformer）采用角色后部分布，进一步考虑了地面响应中使用的实际角色，从而最大程度地减轻了训练和推断之间的差距。此外，我们提出了一个名为IT-Convai2的数据集，该数据集首先突出了个性化对话中的OOP问题。对IT-Convai2和Convai2的广泛实验表明，我们提出的模型在自动指标和人类评估方面都有显着改善。

We investigate response generation for multi-turn dialogue in generative-based chatbots. Existing generative models based on RNNs (Recurrent Neural Networks) usually employ the last hidden state to summarize the sequences, which makes models unable to capture the subtle variability observed in different dialogues and cannot distinguish the differences between dialogues that are similar in composition. In this paper, we propose a Pseudo-Variational Gated Recurrent Unit (PVGRU) component without posterior knowledge through introducing a recurrent summarizing variable into the GRU, which can aggregate the accumulated distribution variations of subsequences. PVGRU can perceive the subtle semantic variability through summarizing variables that are optimized by the devised distribution consistency and reconstruction objectives. In addition, we build a Pseudo-Variational Hierarchical Dialogue (PVHD) model based on PVGRU. Experimental results demonstrate that PVGRU can broadly improve the diversity and relevance of responses on two benchmark datasets.

我们提出了一种新颖的体系结构，用于使用离散的潜在变量对以任务为导向的对话进行解释建模，以表示对话动作。我们的模型基于变异复发性神经网络（VRNN），不需要明确的语义信息注释。与以前的作品不同，我们的方法模型系统和用户单独转动并执行数据库查询建模，这使该模型适用于以任务为导向的对话，同时生成易于解释的可解释的可解释的潜在变量。我们表明，我们的模型在三个数据集中的困惑和BLEU方面优于先前的方法，我们提出了一种衡量对话成功的方法，而无需专家注释。最后，我们提出了一种新颖的方式来解释有关系统动作的潜在变量语义。

Conversational recommender systems (CRSs) often utilize external knowledge graphs (KGs) to introduce rich semantic information and recommend relevant items through natural language dialogues. However, original KGs employed in existing CRSs are often incomplete and sparse, which limits the reasoning capability in recommendation. Moreover, only few of existing studies exploit the dialogue context to dynamically refine knowledge from KGs for better recommendation. To address the above issues, we propose the Variational Reasoning over Incomplete KGs Conversational Recommender (VRICR). Our key idea is to incorporate the large dialogue corpus naturally accompanied with CRSs to enhance the incomplete KGs; and perform dynamic knowledge reasoning conditioned on the dialogue context. Specifically, we denote the dialogue-specific subgraphs of KGs as latent variables with categorical priors for adaptive knowledge graphs refactor. We propose a variational Bayesian method to approximate posterior distributions over dialogue-specific subgraphs, which not only leverages the dialogue corpus for restructuring missing entity relations but also dynamically selects knowledge based on the dialogue context. Finally, we infuse the dialogue-specific subgraphs to decode the recommendation and responses. We conduct experiments on two benchmark CRSs datasets. Experimental results confirm the effectiveness of our proposed method.

目前，基于端到端深度学习的开放域对话系统仍然是黑匣子模型，使其易于与数据驱动的模型生成无关的内容。具体而言，由于缺乏指导培训的先验知识，潜在变量在潜在空间中与不同的语义纠缠在一起。为了解决这个问题，本文提议通过涉及介绍量表特征分离的认知方法来利用生成模型。特别是，该模型将宏观指导类别知识和微观级别的开放域对话数据集成到培训中，并将先验知识利用到潜在空间中，从而使模型能够将潜在变量置于介镜范围内的潜在变量。此外，我们为开放域对话提出了一个新的指标，可以客观地评估潜在空间分布的解释性。最后，我们在不同的数据集上验证了我们的模型，并在实验上证明我们的模型能够比其他模型产生更高的质量和更容易解释的对话。

在过去的几年中，在各种文本生成任务中见证了各种自动编码器的优势。但是，由于文本的顺序性质，自动回归解码器倾向于忽略潜在变量，然后降低到简单的语言模型，称为KL消失的问题，当VAE与基于变压器的结构结合时，这将进一步恶化。为了改善这个问题，我们提出了一种新型变化变压器框架Della。德拉（Della）从较低层的层中得知一系列层的潜在变量，每个变量都从下层的层中推断出，并通过低级张量产品与隐藏状态紧密耦合。通过这种方式，Della强迫这些后部潜在变量将其与整个计算路径深入融合，从而结合了更多信息。从理论上讲，我们可以将我们的方法视为纠缠潜在变量，以避免通过层减少后验信息，从而使DELLA即使没有任何退火或阈值技巧，也可以使DELLA获得更高的非零KL值。与多个强大的基线相比，对四个无条件和三个条件生成任务的实验表明，Della可以更好地减轻KL消失并改善质量和多样性。

深度神经语言模型的最新进展与大规模数据集的能力相结合，加速了自然语言生成系统的发展，这些系统在多种任务和应用程序上下文中产生流利和连贯的文本（在各种成功程度上）。但是，为所需的用户控制这些模型的输出仍然是一个开放的挑战。这不仅对于自定义生成语言的内容和样式至关重要，而且对于他们在现实世界中的安全可靠部署至关重要。我们提出了一项关于受约束神经语言生成的新兴主题的广泛调查，在该主题中，我们通过区分条件和约束（后者是在输出文本上而不是输入的可检验条件），正式定义和分类自然语言生成问题，目前是可检验的）约束文本生成任务，并查看受限文本生成的现有方法和评估指标。我们的目的是强调这个新兴领域的最新进展和趋势，以告知最有希望的方向和局限性，以推动受约束神经语言生成研究的最新作品。

As the functionality of dialogue systems evolves, hybrid dialogue systems that accomplish user-specific goals and participate in open-topic chitchat with users are attracting growing attention. Existing research learns both tasks concurrently utilizing a multi-task fusion technique but ignores the negative transfer phenomenon induced by the unique textual style differences. Therefore, contrastive learning based on the latent variable model is used to decouple the various textual genres in the latent space. We devise supervised and self-supervised positive and negative sample constructions for diverse datasets. In addition, to capitalize on the style information contained in the decoupled latent variables, we employ a style prefix that incorporates latent variables further to control the generation of responses with varying styles. We performed extensive experiments on three dialogue datasets, including a hybrid dialogue dataset and two task-oriented dialogue datasets. The experimental results demonstrate that our method can mitigate the negative style transfer issue and achieves state-of-the-art performance on multiple dialogue datasets.

Long-range context modeling is crucial to both dialogue understanding and generation. The most popular method for dialogue context representation is to concatenate the last-$k$ previous utterances. However, this method may not be ideal for conversations containing long-range dependencies. In this work, we propose DialoGX, a novel encoder-decoder based framework for conversational response generation with a generalized and explainable context representation that can look beyond the last-$k$ utterances. Hence the method is adaptive to conversations with long-range dependencies. The main idea of our approach is to identify and utilize the most relevant historical utterances instead of the last-$k$ utterances in chronological order. We study the effectiveness of our proposed method on both dialogue generation (open-domain) and understanding (DST) tasks. DialoGX achieves comparable performance with the state-of-the-art models on DailyDialog dataset. We also observe performance gain in existing DST models with our proposed context representation strategy on MultiWOZ dataset. We justify our context representation through the lens of psycholinguistics and show that the relevance score of previous utterances agrees well with human cognition which makes DialoGX explainable as well.

Natural Language Generation (NLG) has improved exponentially in recent years thanks to the development of sequence-to-sequence deep learning technologies such as Transformer-based language models. This advancement has led to more fluent and coherent NLG, leading to improved development in downstream tasks such as abstractive summarization, dialogue generation and data-to-text generation. However, it is also apparent that deep learning based generation is prone to hallucinate unintended text, which degrades the system performance and fails to meet user expectations in many real-world scenarios. To address this issue, many studies have been presented in measuring and mitigating hallucinated texts, but these have never been reviewed in a comprehensive manner before. In this survey, we thus provide a broad overview of the research progress and challenges in the hallucination problem in NLG. The survey is organized into two parts: (1) a general overview of metrics, mitigation methods, and future directions; and (2) an overview of task-specific research progress on hallucinations in the following downstream tasks, namely abstractive summarization, dialogue generation, generative question answering, data-to-text generation, machine translation, and visual-language generation. This survey serves to facilitate collaborative efforts among researchers in tackling the challenge of hallucinated texts in NLG.

最近的知识接地对话框方法通过从外部文本文档中包含信息来生成响应。这些方法不需要在训练期间知道确切的文件，并依赖于使用检索系统来从大型索引获取相关文档。用于生成响应的文档被建模为潜在的变量，其先验概率需要估计。诸如rag等型号，在从索引中检索的文档上边缘化文档概率，以定义对端到端优化的日志似然丢失函数。在本文中，我们开发了上述技术的变分方法，据称，我们最大化证据下限（ELBO）。使用三个公开可用的开放式对话数据集的集合，我们展示了与地面真相响应的信息的后部分布如何允许在训练期间更好地逼近客观函数。为了克服与大型知识收集相关的抽样相关的挑战，我们开发了一种高效的方法来近似eLBO。据我们所知，我们是第一个适用于开放式无监督知识接地对话系统的变分培训。

Complex dialogue mappings (CDM), including one-to-many and many-to-one mappings, tend to make dialogue models generate incoherent or dull responses, and modeling these mappings remains a huge challenge for neural dialogue systems. To alleviate these problems, methods like introducing external information, reconstructing the optimization function, and manipulating data samples are proposed, while they primarily focus on avoiding training with CDM, inevitably weakening the model's ability of understanding CDM in human conversations and limiting further improvements in model performance. This paper proposes a Sentence Semantic \textbf{Seg}mentation guided \textbf{C}onditional \textbf{V}ariational \textbf{A}uto-\textbf{E}ncoder (SegCVAE) method which can model and take advantages of the CDM data. Specifically, to tackle the incoherent problem caused by one-to-many, SegCVAE uses response-related prominent semantics to constrained the latent variable. To mitigate the non-diverse problem brought by many-to-one, SegCVAE segments multiple prominent semantics to enrich the latent variables. Three novel components, Internal Separation, External Guidance, and Semantic Norms, are proposed to achieve SegCVAE. On dialogue generation tasks, both the automatic and human evaluation results show that SegCVAE achieves new state-of-the-art performance.

医学对话生成是一项重要但具有挑战性的任务。以前的大多数作品都依赖于注意力机制和大规模预处理的语言模型。但是，这些方法通常无法从长时间的对话历史中获取关键信息，从而产生准确和信息丰富的响应，因为医疗实体通常散布在多种话语中以及它们之间的复杂关系。为了减轻此问题，我们提出了一个具有关键信息召回（Medpir）的医疗响应生成模型，该模型建立在两个组件上，即知识吸引的对话图形编码器和召回增强的生成器。知识吸引的对话图编码器通过利用话语中的实体之间的知识关系，并使用图形注意力网络对话图来构建对话图。然后，召回增强的发电机通过在产生实际响应之前生成对话的摘要来增强这些关键信息的使用。两个大型医学对话数据集的实验结果表明，Medpir在BLEU分数和医疗实体F1度量中的表现优于强大的基准。

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 opendomain dialogue systems.

本文对过去二十年来对自然语言生成（NLG）的研究提供了全面的审查，特别是与数据到文本生成和文本到文本生成深度学习方法有关，以及NLG的新应用技术。该调查旨在（a）给出关于NLG核心任务的最新综合，以及该领域采用的建筑;（b）详细介绍各种NLG任务和数据集，并提请注意NLG评估中的挑战，专注于不同的评估方法及其关系;（c）强调一些未来的强调和相对近期的研究问题，因为NLG和其他人工智能领域的协同作用而增加，例如计算机视觉，文本和计算创造力。