Retrieval-augmented in-context learning has emerged as a powerful approach for addressing knowledge-intensive tasks using frozen language models (LM) and retrieval models (RM). Existing work has combined these in simple "retrieve-then-read" pipelines in which the RM retrieves passages that are inserted into the LM prompt. To begin to fully realize the potential of frozen LMs and RMs, we propose Demonstrate-Search-Predict (DSP), a framework that relies on passing natural language texts in sophisticated pipelines between an LM and an RM. DSP can express high-level programs that bootstrap pipeline-aware demonstrations, search for relevant passages, and generate grounded predictions, systematically breaking down problems into small transformations that the LM and RM can handle more reliably. We have written novel DSP programs for answering questions in open-domain, multi-hop, and conversational settings, establishing in early evaluations new state-of-the-art in-context learning results and delivering 37-200%, 8-40%, and 80-290% relative gains against vanilla LMs, a standard retrieve-then-read pipeline, and a contemporaneous self-ask pipeline, respectively.
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Language tasks involving character-level manipulations (e.g., spelling correction, many word games) are challenging for models based in subword tokenization. To address this, we adapt the interchange intervention training method of Geiger et al. (2021) to operate on type-level variables over characters. This allows us to encode robust, position-independent character-level information in the internal representations of subword-based models. We additionally introduce a suite of character-level tasks that systematically vary in their dependence on meaning and sequence-level context. While simple character-level tokenization approaches still perform best on purely form-based tasks like string reversal, our method is superior for more complex tasks that blend form, meaning, and context, such as spelling correction in context and word search games. Our approach also leads to subword-based models with human-intepretable internal representations of characters.
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The COVID-19 pandemic created a deluge of questionable and contradictory scientific claims about drug efficacy -- an "infodemic" with lasting consequences for science and society. In this work, we argue that NLP models can help domain experts distill and understand the literature in this complex, high-stakes area. Our task is to automatically identify contradictory claims about COVID-19 drug efficacy. We frame this as a natural language inference problem and offer a new NLI dataset created by domain experts. The NLI framing allows us to create curricula combining existing datasets and our own. The resulting models are useful investigative tools. We provide a case study of how these models help a domain expert summarize and assess evidence concerning remdisivir and hydroxychloroquine.
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Neural information retrieval (IR) systems have progressed rapidly in recent years, in large part due to the release of publicly available benchmarking tasks. Unfortunately, some dimensions of this progress are illusory: the majority of the popular IR benchmarks today focus exclusively on downstream task accuracy and thus conceal the costs incurred by systems that trade away efficiency for quality. Latency, hardware cost, and other efficiency considerations are paramount to the deployment of IR systems in user-facing settings. We propose that IR benchmarks structure their evaluation methodology to include not only metrics of accuracy, but also efficiency considerations such as a query latency and the corresponding cost budget for a reproducible hardware setting. For the popular IR benchmarks MS MARCO and XOR-TyDi, we show how the best choice of IR system varies according to how these efficiency considerations are chosen and weighed. We hope that future benchmarks will adopt these guidelines toward more holistic IR evaluation.
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NLP系统的解释性方法遇到了因果推断的基本问题的版本:对于给定的基础真相输入文本,我们从未真正观察到隔离模型表示对输出的因果影响所必需的反事实文本。作为回应,许多解释性方法不使用反事实文本,假设它们将是不可用的。在本文中,我们表明可以使用近似反事实来创建强大的因果解释方法,该方法可以由人类写成近似特定的反事实或简单地使用元数据指导的启发式启发式启示术进行采样。我们提案的核心是因果替代模型(CPM)。 CPM解释了一个黑框$ \ Mathcal {n} $,因为它经过培训可以具有与$ \ Mathcal {n} $相同的实际输入/输出行为,而创建可以介入的神经表示,以模拟反事实输入/$ \ MATHCAL {N} $的输出行为。此外,我们证明了$ \ Mathcal {n} $的最佳CPM在做出事实预测时性能与$ \ Mathcal {n} $相当地执行,这意味着CPM可以简单地替换$ \ Mathcal {n} $,从而导致更多信息可解释的部署模型。我们的代码可在https://github.com/frankaging/causal-proxy-model上找到。
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语言模型既展示了定量的改进,又展示了新的定性功能,随着规模的增加。尽管它们具有潜在的变革性影响,但这些新能力的特征却很差。为了为未来的研究提供信息,为破坏性的新模型能力做准备,并改善社会有害的效果,至关重要的是,我们必须了解目前和近乎未来的能力和语言模型的局限性。为了应对这一挑战,我们介绍了超越模仿游戏基准(Big Bench)。 Big Bench目前由204个任务组成,由132家机构的442位作者贡献。任务主题是多样的,从语言学,儿童发展,数学,常识性推理,生物学,物理学,社会偏见,软件开发等等。 Big-Bench专注于被认为超出当前语言模型的功能的任务。我们评估了OpenAI的GPT型号,Google内部密集变压器体系结构和大型基础上的开关稀疏变压器的行为,跨越了数百万到数十亿个参数。此外,一个人类专家评估者团队执行了所有任务,以提供强大的基准。研究结果包括:模型性能和校准都随规模改善,但绝对的术语(以及与评估者的性能相比);在模型类中的性能非常相似,尽管带有稀疏性。逐渐和预测的任务通常涉及大量知识或记忆成分,而在临界规模上表现出“突破性”行为的任务通常涉及多个步骤或组成部分或脆性指标;社交偏见通常会随着含糊不清的环境而随着规模而增加,但这可以通过提示来改善。
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蒸馏工作导致语言模型更紧凑,没有严重的性能下降。蒸馏的标准方法培训了针对两个目标的学生模型:特定于任务的目标(例如,语言建模)和模仿目标,并鼓励学生模型的隐藏状态与较大的教师模型类似。在本文中,我们表明,增强蒸馏有利于第三个目标,鼓励学生通过交换干预培训(IIT)来模仿教师的因果计算过程。 IIT推动学生模型成为教师模型的因果抽象 - 一种具有相同因果结构的更简单的模型。 IIT是完全可差异的,容易实施,并与其他目标灵活结合。与伯特标准蒸馏相比,通过IIT蒸馏导致维基百科(屏蔽语言建模)逐步困惑,并对胶水基准(自然语言理解),队(问题接听)和Conll-2003(命名实体识别)进行了改进。
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神经信息检索(IR)具有极大的搜索和其他知识密集型语言任务。虽然许多神经IR方法将查询和文档编码为单载表示,但后期交互模型在每个令牌的粒度下产生多向量表示,并将相关性建模分解为可伸缩的令牌级计算。这种分解已被证明可以使迟到的交互更有效,但它以幅度的数量级膨胀这些模型的空间占地面积。在这项工作中,我们介绍了Colbertv2,这是一种猎犬,其与去噪的监督策略相结合的侵略性的残余压缩机制,同时提高晚期互动的质量和空间足迹。我们在各种基准中评估COLBertv2,在培训域内和外部建立最先进的质量,同时减少了晚期互动模型的空间足迹5-8 $ \ times $。
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在许多领域,我们有很好的了解有关导致结构的洞察,这将使我们训练有素的型号有用,同时仍然可以以数据驱动的方式学习。为此,我们介绍了交换干预培训的新方法(IIT)。在IIT中,我们(1)与神经模型中的表示的因果模型中的变量和(2)列车在一个神经模型中,以匹配当两个模型中的对齐表示时的基本输入上的因果模型的反事行为它们是第二源输入的值。 IIT完全可分辨,灵活地与其他目标结合,并保证目标因果模型是当其损失最小化时神经模型的ACAUSAL抽象。我们在结构化视觉任务(MNIST-PVR)和导航指令任务(REARCAN)上评估IIT。我们将IIT与多任务培训目标和数据增强进行比较。在我们的所有实验中,IIT在他们实现目标因果模型的意义上实现了最佳结果,并产生了更可观的诠释。
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AI正在经历范式转变,随着模型的兴起(例如Bert,Dall-E,GPT-3),这些模型经过大规模的数据训练,并且可以适应广泛的下游任务。我们称这些模型基础模型来强调其至关重要但不完整的特征。该报告提供了基础模型的机会和风险的详尽说明,包括其功能(例如语言,愿景,机器人技术,推理,人类互动)和技术原则(例如,模型架构,培训程序,数据,系统,安全,安全性,评估,理论)对其应用(例如法律,医疗保健,教育)和社会影响(例如不平等,滥用,经济和环境影响,法律和道德考虑)。尽管基础模型基于标准的深度学习和转移学习,但它们的规模导致了新的新兴能力,以及它们在许多任务中的有效性都激发了同质化。同质化提供了强大的杠杆作用,但要求谨慎,因为基础模型的缺陷均由下游的所有适应模型继承。尽管即将广泛地部署基础模型,但我们目前对它们的工作方式,失败以及由于其新兴属性的影响而缺乏清晰的了解。为了解决这些问题,我们认为基础模型的许多批判性研究都需要与他们的基本社会技术性质相称。
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