Constructing A Multi-hop QA Dataset for Comprehensive Evaluation of Reasoning Steps

TL;DR

Proposes 2WikiMultiHopQA, combining structured and unstructured data, with explicit reasoning paths, enhancing interpretability and reasoning evaluation.

cs.CL 🔴 Advanced 2020-11-02 34 views
Xanh Ho Anh-Khoa Duong Nguyen Saku Sugawara Akiko Aizawa
multi-hop QA knowledge graph reasoning path structured data NLU

Key Findings

Methodology

This work constructs a large-scale multi-hop QA dataset by integrating Wikipedia texts and Wikidata triples. Using template-based question generation and logical rules, it ensures questions require multi-hop reasoning. Evidence information, representing reasoning paths, is incorporated to improve interpretability. An automated pipeline generates diverse question types—comparison, inference, compositional, and bridge—covering various reasoning scenarios. The dataset is split into train, dev, and test sets, with evaluation using joint metrics for answer, supporting facts, and evidence. Experiments with single-hop BERT models show the dataset's high difficulty, with performance significantly lower than human upper bounds, confirming its challenge for current models.

Key Results

  • The dataset contains 192,606 questions across four reasoning types, with an average F1 of 40.95, surpassing HotpotQA in difficulty. Model F1 on answer prediction is 34.14, 8.7 points lower than HotpotQA, indicating increased complexity.
  • Incorporating explicit reasoning paths enhances model interpretability, though path prediction remains challenging. Performance varies across question types, with inference and bridge questions being most difficult.
  • Compared to human upper bounds (F1 ~91), models lag considerably, highlighting the need for improved reasoning and explanation mechanisms.

Significance

This dataset addresses the limitations of existing multi-hop QA benchmarks lacking explicit reasoning paths, providing a challenging and explainable platform. It advances the integration of structured knowledge with unstructured text, promoting models that can perform deep reasoning with interpretability. The evidence path mechanism offers a new paradigm for explainable AI, crucial for real-world applications like medical diagnosis, legal reasoning, and decision support. It sets a new standard for evaluating multi-hop reasoning, fostering innovation in model architectures and training strategies.

Technical Contribution

The paper introduces a systematic approach to generate multi-hop questions by combining logical rules from knowledge graphs with template-based natural language questions. It leverages Wikidata's structured triples and Wikipedia's text to create diverse, high-quality datasets with explicit reasoning paths. The pipeline automates question and evidence generation, ensuring consistency and complexity. The approach also integrates logical inference rules to produce natural yet challenging questions, significantly advancing the state-of-the-art in dataset construction for multi-hop QA. The evidence information enhances model explainability, a crucial step toward trustworthy AI.

Novelty

This is the first work to systematically combine structured knowledge graphs with unstructured text to generate a large-scale, multi-hop QA dataset with explicit reasoning paths. Unlike prior datasets like HotpotQA, which only provide sentence support facts, 2WikiMultiHopQA offers complete reasoning paths with triples, enabling models to learn and explain complex inference chains. The logical rule-based question generation ensures naturalness and multi-hop complexity, representing a significant innovation in dataset creation and evaluation for multi-hop reasoning.

Limitations

  • The dataset generation relies heavily on predefined templates and logical rules, which may limit linguistic diversity and naturalness, potentially affecting generalization to real-world scenarios.
  • Automatic evidence path generation, while effective, can introduce errors, impacting the accuracy of reasoning explanations.
  • Current models still struggle with precise evidence path prediction, indicating the need for more sophisticated reasoning architectures and training strategies.

Future Work

Future directions include enhancing the naturalness and diversity of generated questions, integrating multimodal data (images, videos) for richer reasoning contexts, and developing end-to-end models capable of jointly learning question answering and evidence path reasoning. Expanding logical rule sets and incorporating neural symbolic reasoning could further improve reasoning depth. Additionally, applying this framework to other languages and domains, such as biomedical or legal texts, will broaden its impact. Ultimately, the goal is to create AI systems capable of human-like reasoning and explanation, applicable in real-world complex decision-making tasks.

AI Executive Summary

Multi-hop question answering (QA) has become a vital area in natural language understanding, aiming to emulate human reasoning over multiple information sources. Existing datasets like HotpotQA have driven progress but often lack explicit, complete reasoning paths, limiting models’ interpretability and depth of reasoning. To address this, the present study introduces 2WikiMultiHopQA, a large-scale dataset that combines structured knowledge from Wikidata with unstructured Wikipedia texts. This integration enables the construction of questions that inherently require multiple reasoning steps, with explicit evidence paths represented as triples, providing transparent explanations.

The dataset is generated through an automated pipeline that employs logical rules and templates to ensure questions demand multi-hop inference. It covers four key reasoning types—comparison, inference, compositional, and bridge questions—mirroring real-world complexity. Experimental evaluations with baseline models reveal that the dataset is significantly more challenging than HotpotQA, with model performance notably lower, especially on inference and bridge questions. Human upper bounds demonstrate the potential for further improvements.

This work advances the field by offering a comprehensive, explainable benchmark for multi-hop reasoning. Its combination of structured and unstructured data, along with explicit reasoning paths, paves the way for developing more interpretable and robust AI systems. While promising, challenges remain in natural language diversity and reasoning accuracy, guiding future research toward more sophisticated models and richer data generation techniques. Overall, 2WikiMultiHopQA sets a new standard for evaluating and enhancing multi-hop reasoning capabilities in AI.

Deep Analysis

Background

多跳问答(QA)旨在模拟人类复杂推理过程,近年来随着大规模预训练模型的兴起,推动了该领域的快速发展。早期工作如HotpotQA、QAngaroo等,主要关注句子支持事实,缺乏完整推理路径,限制了模型的可解释性和推理深度。知识图谱的引入为推理提供了结构化基础,但现有数据集普遍存在推理路径不完整、自然性不足的问题。近年来,结合结构化知识与非结构化文本的研究逐渐成为热点,试图解决推理路径不透明和多样性不足的难题。本研究在此基础上,提出了结合逻辑规则和自动化模板的生成框架,旨在构建具有完整推理路径的多跳问答数据集,为模型提供更丰富的训练和评估资源。

Core Problem

当前多跳问答数据集存在推理路径不完整、缺乏结构化解释的问题,导致模型难以学习到真实的推理过程。许多数据中的问题可以通过浅层特征或单跳推理解决,未能充分考验模型的深层推理能力。此外,缺乏结构化推理路径使得模型难以提供可信的解释,限制了其在实际应用中的推广。如何设计既自然又具备多跳推理需求的问题,且能提供完整推理路径,成为核心挑战。这不仅关系到模型的推理深度,也影响其在复杂场景中的应用效果。

Innovation

本研究的创新主要体现在:1)结合结构化知识图谱(Wikidata)和非结构化文本(维基百科),自动生成具有完整推理路径的多跳问题;2)利用逻辑规则从知识图谱中推导复杂关系,确保问题的合理性和多样性;3)引入证据路径作为自然语言描述,增强模型的可解释性;4)设计自动化Pipeline,保证数据的质量和多样性。这些创新突破了以往仅依赖句子支持事实的局限,为多跳推理提供了更真实、更丰富的训练和评估平台。

Methodology

  • �� 设计模板:基于实体识别,手工和自动生成多类别问题模板,确保多跳特性。• 数据生成:利用逻辑规则和关系,自动生成多跳问题,确保推理路径合理。• 证据路径:从知识图谱中提取推理路径,作为自然语言描述。• 数据划分:采用五折交叉验证,确保训练、验证、测试集的代表性。• 模型评估:使用Answer、Supporting Facts和Evidence的联合指标,全面衡量性能。• 逻辑验证:筛选和验证逻辑规则,确保推理正确性。• 多样问题:涵盖比较、推理、组合、桥接,丰富任务场景。

Experiments

采用维基百科和Wikidata作为数据源,自动生成192,606个多跳问题。使用单跳BERT模型进行性能评估,F1为34.14,低于HotpotQA的44.48,验证了数据集的挑战性。不同类别问题表现差异明显,推理和桥接问题最难。与人类性能上限对比,模型差距明显,验证了推理路径的重要性。实验还包括逻辑规则验证、数据质量分析和误差分析,为未来改进提供依据。

Results

新数据集难度高于HotpotQA,模型F1降低8.7,验证多跳推理的复杂性。引入证据路径提升解释性,但路径预测仍有误差。不同类型问题表现差异显著,推理和桥接问题最具挑战。人类性能远超模型,显示未来提升空间。整体验证了数据集的有效性和挑战性,为多跳推理模型提供了强有力的评估平台。

Applications

该数据集适用于训练和评估具有深层推理能力的问答系统,特别适合知识丰富、推理复杂的场景,如智能助手、信息检索和决策支持。未来可结合多模态信息,拓展到图像、视频等多源数据,提升系统的智能水平。长远目标是实现更具推理深度和解释性的AI系统,改善人机交互体验,应用于医疗、法律等专业领域。

Limitations & Outlook

数据生成依赖模板和逻辑规则,可能导致问题缺乏自然多样性,影响模型泛化能力。自动证据路径生成存在误差,影响推理解释的准确性。模型在路径预测和复杂推理方面仍有较大提升空间。未来需引入更复杂的自然语言生成和推理机制,增强数据多样性和推理深度。

Plain Language Accessible to non-experts

想象你在一个工厂里工作,工厂里有很多不同的机器和流程。每个机器都能做特定的事情,但要完成一个复杂的任务,比如制造一辆汽车,你需要多个步骤合作。你得先装车架,然后装引擎,再装轮子,每一步都需要前一步的结果。这个过程就像多跳推理:每个步骤都依赖前面的信息,最后才能得到完整的答案。这个研究就像设计一个智能工厂,让它知道每个步骤怎么连接,能自己找到制造汽车的完整流程,还能解释每一步是怎么做的。这样,工厂(模型)不仅能完成任务,还能告诉你它是怎么想到的,变得更聪明、更可信。

ELI14 Explained like you're 14

想象你在玩一个超级复杂的拼图游戏,你不仅要找到拼图块,还要知道每个块是怎么拼在一起的。有时候,你需要先拼出一部分,然后用这部分信息去拼另一部分。这个研究就像设计一个聪明的拼图助手,它可以帮你找到每个拼图块的正确位置,还能告诉你它是怎么拼出来的。它不仅能帮你完成拼图,还能解释每一步是怎么拼的,就像告诉你拼图的秘密一样。这个助手用了一些聪明的规则和方法,确保每个拼图步骤都合理。虽然还不完美,但它让拼图变得更容易,也让你更懂拼图的奥秘!

Glossary

Multi-hop QA(多跳问答)

一种问答任务,要求模型通过多次推理连接多个信息片段以找到答案。技术上涉及多轮信息融合与推理路径建模。

论文中提出的核心任务类型。

证据信息(Evidence)

描述推理路径的结构化或自然语言信息,帮助模型解释推理过程。技术上为一组三元组或路径描述。

用于增强模型解释性的重要组成部分。

逻辑规则(Logical Rules)

基于知识图谱中的关系定义的推理规则,用于自动生成复杂问题。技术上为蕴含关系或推理模板。

自动生成多跳问题的基础。

Wikidata(维基数据)

一个结构化的知识库,存储实体及其关系,支持推理路径的自动提取。

数据源之一,用于构建问题和推理路径。

Answer Prediction(答案预测)

模型根据问题和上下文输出答案的任务。技术上为Span抽取或生成模型。

评估模型理解和推理能力的核心任务。

Open Questions Unanswered questions from this research

  • 1 如何进一步提升证据路径的自动生成质量,确保其自然性和多样性,仍是未来研究的关键。当前逻辑规则有限,难以涵盖所有推理场景,亟需引入更复杂的推理机制。

Applications

Immediate Applications

智能问答系统

可用于构建更具推理能力的智能助手,提升信息检索和决策支持的准确性与可信度。

知识图谱推理

帮助知识库自动生成推理路径,增强知识的可解释性和应用范围。

Long-term Vision

人机交互革新

实现更自然、更可信的对话系统,支持复杂推理和解释,推动AI在医疗、法律等领域的应用。

Abstract

A multi-hop question answering (QA) dataset aims to test reasoning and inference skills by requiring a model to read multiple paragraphs to answer a given question. However, current datasets do not provide a complete explanation for the reasoning process from the question to the answer. Further, previous studies revealed that many examples in existing multi-hop datasets do not require multi-hop reasoning to answer a question. In this study, we present a new multi-hop QA dataset, called 2WikiMultiHopQA, which uses structured and unstructured data. In our dataset, we introduce the evidence information containing a reasoning path for multi-hop questions. The evidence information has two benefits: (i) providing a comprehensive explanation for predictions and (ii) evaluating the reasoning skills of a model. We carefully design a pipeline and a set of templates when generating a question-answer pair that guarantees the multi-hop steps and the quality of the questions. We also exploit the structured format in Wikidata and use logical rules to create questions that are natural but still require multi-hop reasoning. Through experiments, we demonstrate that our dataset is challenging for multi-hop models and it ensures that multi-hop reasoning is required.

cs.CL