Abstractive dialogue summarization has long been viewed as an important standalone task in natural language processing, but no previous work has explored the possibility of whether abstractive dialogue summarization can also be used as a means to boost an NLP system's performance on other important dialogue comprehension tasks. In this paper, we propose a novel type of dialogue summarization task - STRUctured DiaLoguE Summarization - that can help pre-trained language models to better understand dialogues and improve their performance on important dialogue comprehension tasks. We further collect human annotations of STRUDEL summaries over 400 dialogues and introduce a new STRUDEL dialogue comprehension modeling framework that integrates STRUDEL into a graph-neural-network-based dialogue reasoning module over transformer encoder language models to improve their dialogue comprehension abilities. In our empirical experiments on two important downstream dialogue comprehension tasks - dialogue question answering and dialogue response prediction - we show that our STRUDEL dialogue comprehension model can significantly improve the dialogue comprehension performance of transformer encoder language models.
translated by 谷歌翻译
Recent work has shown that fine-tuning large pre-trained language models on a collection of tasks described via instructions, a.k.a. instruction-tuning, improves their zero and few-shot generalization to unseen tasks. However, there is a limited understanding of the performance trade-offs of different decisions made during the instruction-tuning process. These decisions include the scale and diversity of the instruction-tuning benchmark, different task sampling strategies, fine-tuning with and without demonstrations, training using specialized datasets for reasoning and dialogue, and finally, the fine-tuning objectives themselves. In this paper, we characterize the effect of instruction-tuning decisions on downstream task performance when scaling both model and benchmark sizes. To this end, we create OPT-IML Bench: a large benchmark for Instruction Meta-Learning (IML) of 2000 NLP tasks consolidated into task categories from 8 existing benchmarks, and prepare an evaluation framework to measure three types of model generalizations: to tasks from fully held-out categories, to held-out tasks from seen categories, and to held-out instances from seen tasks. Through the lens of this framework, we first present insights about instruction-tuning decisions as applied to OPT-30B and further exploit these insights to train OPT-IML 30B and 175B, which are instruction-tuned versions of OPT. OPT-IML demonstrates all three generalization abilities at both scales on four different evaluation benchmarks with diverse tasks and input formats -- PromptSource, FLAN, Super-NaturalInstructions, and UnifiedSKG. Not only does it significantly outperform OPT on all benchmarks but is also highly competitive with existing models fine-tuned on each specific benchmark. We release OPT-IML at both scales, together with the OPT-IML Bench evaluation framework.
translated by 谷歌翻译
Lack of factual correctness is an issue that still plagues state-of-the-art summarization systems despite their impressive progress on generating seemingly fluent summaries. In this paper, we show that factual inconsistency can be caused by irrelevant parts of the input text, which act as confounders. To that end, we leverage information-theoretic measures of causal effects to quantify the amount of confounding and precisely quantify how they affect the summarization performance. Based on insights derived from our theoretical results, we design a simple multi-task model to control such confounding by leveraging human-annotated relevant sentences when available. Crucially, we give a principled characterization of data distributions where such confounding can be large thereby necessitating the use of human annotated relevant sentences to generate factual summaries. Our approach improves faithfulness scores by 20\% over strong baselines on AnswerSumm \citep{fabbri2021answersumm}, a conversation summarization dataset where lack of faithfulness is a significant issue due to the subjective nature of the task. Our best method achieves the highest faithfulness score while also achieving state-of-the-art results on standard metrics like ROUGE and METEOR. We corroborate these improvements through human evaluation.
translated by 谷歌翻译
Prompting large language models has enabled significant recent progress in multi-step reasoning over text. However, when applied to text generation from semi-structured data (e.g., graphs or tables), these methods typically suffer from low semantic coverage, hallucination, and logical inconsistency. We propose MURMUR, a neuro-symbolic modular approach to text generation from semi-structured data with multi-step reasoning. MURMUR is a best-first search method that generates reasoning paths using: (1) neural and symbolic modules with specific linguistic and logical skills, (2) a grammar whose production rules define valid compositions of modules, and (3) value functions that assess the quality of each reasoning step. We conduct experiments on two diverse data-to-text generation tasks like WebNLG and LogicNLG. These tasks differ in their data representations (graphs and tables) and span multiple linguistic and logical skills. MURMUR obtains significant improvements over recent few-shot baselines like direct prompting and chain-of-thought prompting, while also achieving comparable performance to fine-tuned GPT-2 on out-of-domain data. Moreover, human evaluation shows that MURMUR generates highly faithful and correct reasoning paths that lead to 26% more logically consistent summaries on LogicNLG, compared to direct prompting.
translated by 谷歌翻译
Current large language models can perform reasonably well on complex tasks that require step-by-step reasoning with few-shot learning. Are these models applying reasoning skills they have learnt during pre-training and reason outside of their training context, or are they simply memorizing their training corpus at finer granularity and have learnt to better understand their context? To tease apart these possibilities, we introduce ALERT, a benchmark and suite of analyses for assessing language models' reasoning ability comparing pre-trained and finetuned models on complex tasks that require reasoning skills to solve. ALERT provides a test bed to asses any language model on fine-grained reasoning skills, which spans over 20 datasets and covers 10 different reasoning skills. We leverage ALERT to further investigate the role of finetuning. With extensive empirical analysis we find that language models learn more reasoning skills such as textual entailment, abductive reasoning, and analogical reasoning during finetuning stage compared to pretraining state. We also find that when language models are finetuned they tend to overfit to the prompt template, which hurts the robustness of models causing generalization problems.
translated by 谷歌翻译
Large language models show improved downstream task performance when prompted to generate step-by-step reasoning to justify their final answers. These reasoning steps greatly improve model interpretability and verification, but objectively studying their correctness (independent of the final answer) is difficult without reliable methods for automatic evaluation. We simply do not know how often the stated reasoning steps actually support the final end task predictions. In this work, we present ROSCOE, a suite of interpretable, unsupervised automatic scores that improve and extend previous text generation evaluation metrics. To evaluate ROSCOE against baseline metrics, we design a typology of reasoning errors and collect synthetic and human evaluation scores on commonly used reasoning datasets. In contrast with existing metrics, ROSCOE can measure semantic consistency, logicality, informativeness, fluency, and factuality - among other traits - by leveraging properties of step-by-step rationales. We empirically verify the strength of our metrics on five human annotated and six programmatically perturbed diagnostics datasets - covering a diverse set of tasks that require reasoning skills and show that ROSCOE can consistently outperform baseline metrics.
translated by 谷歌翻译
基于变压器的模型的出现,机器翻译已经快速发展。这些模型没有内置的明确的语言结构,但是它们仍然可以通过参与相关令牌隐式学习结构化的关系。我们假设通过明确赋予变形金刚具有结构性偏见,可以使这种结构学习变得更加健壮,我们研究了两种在这种偏见中构建的方法。一种方法,即TP变换器,可以增强传统的变压器体系结构,包括代表结构的附加组件。第二种方法通过将数据分割为形态令牌化来灌输数据级别的结构。我们测试了这些方法从英语翻译成土耳其语和Inuktitut的形态丰富的语言,并考虑自动指标和人类评估。我们发现,这两种方法中每种方法都允许网络实现更好的性能,但是此改进取决于数据集的大小。总而言之,结构编码方法使变压器更具样本效率,从而使它们能够从少量数据中表现得更好。
translated by 谷歌翻译
生成摘要中的事实不一致严重限制了抽象对话摘要的实际应用。尽管通过使用预先训练的模型实现了显着进展,但在人类评估期间发现了大量的幻觉含量。预先接受的模型最常见的是微调文本摘要的跨熵损失,这可能不是最佳策略。在这项工作中,我们为带注释数据提供了事实错误的类型,以突出显示错误的类型并远离对事实的二进制了解。我们进一步提出了一种培训策略,通过新颖的对比微调,改善了摘要的事实一致性和整体素质。基于我们的语言信息的错误类型,我们设计了各个目标的不同模块化目标。具体而言,我们利用硬阴性样本具有误差,以减少事实不一致的产生。为了捕获扬声器之间的关键信息,我们还设计了特定于对话的损失。使用人类评估和自动忠实度量指标,我们表明我们的模型在对话摘要,Samsum语料库中大大降低了各种事实错误。此外,我们的模型可以推广到会议概述,AMI语料库,它产生的分数明显高于两个数据集关于单词 - 重叠度量标准的基线。
translated by 谷歌翻译
最近延伸预留下芬特的神经模型的神经模型继续实现新的最新导致对话状态跟踪(DST)基准的联合目标准确性(JGA)。但是,我们调查了他们的稳健性,因为它们在JGA中显示了急剧下降,以便与现实扰动的话语或对话框流动的对话。通过清单(Ribeiro等,2020),我们设计了一个名为CheckDST的度量集合,促进DST模型的比较,通过测试具有增强测试集的众所周知的弱点来促进革命性的全面尺寸。我们使用CheckDST评估最近的DST模型,并认为模型应该更全面地评估,而不是在JGA上追求最先进的JGA,因为更高的JGA不保证更好的整体稳健性。我们发现基于跨度的分类模型是有弹性的,不合适的命名实体,但对语言品种不强大,而那些基于自回归语言模型的人概括为语言变化,但往往会记住命名实体并往往是幻觉。由于它们各自的弱点,两种方法都不适合现实世界部署。我们认为CheckDst是未来研究的一个有用指南,用于开发面向任务的对话模型,体现了各种方法的优势。
translated by 谷歌翻译
当前有效的微调方法(例如,适配器,前缀调整等)通过培训一小组神经语言模型的额外参数进行优化的条件文本生成,同时冻结其余效率。虽然在某些一代任务中显示出强大表现,但它们不会概括所有一代任务。在这项工作中,我们表明可以提高基于迅速的条件文本生成,简单而有效的方法模拟了人类书面文本的话语结构建模。我们介绍了两个关键设计选择:首先,我们表明人写文本的更高级别的话语结构可以用前缀参数上的\ Textit {分层阻塞}建模,使得能够跨越输入和输出文本的不同部分,并产生更长度的输出几代人。其次,我们通过在网络上的不同层的前缀参数上引入\ texit {注意稀疏性}来提出稀疏的前缀调整,并分别学习SoftMax函数上的稀疏变换。我们发现稀疏的注意力使前缀调整能够更好地控制输入内容(突出事实),从而更有效地调整前缀参数。在各种文本生成任务上的实验表明,前缀参数的结构化设计可以实现可比的结果,以微调所有参数,同时即使在低资源设置中也表现出所有生成任务的标准前缀调整。
translated by 谷歌翻译