BoolQ: Exploring the Surprising Difficulty of Natural Yes/No Questions
Christopher ClarkKenton LeeMing-Wei ChangTom KwiatkowskiMichael CollinsKristina Toutanova
Introduces BoolQ, a benchmark of naturally occurring yes/no questions, establishing that natural binary queries demand complex inference beyond standard extractive reading comprehension and reveal substantial reasoning gaps in advanced language models.
The article addresses the challenge of building reading comprehension systems that can handle naturally occurring yes/no questions, which often require complex inferences beyond simple fact lookup or paraphrasing. Such questions arise frequently in real user queries yet remain difficult for current models, creating a gap between benchmark performance and practical utility.
The article set out to create a dedicated dataset of these questions and to measure how effectively transfer learning from related tasks could solve them.
The authors collected 16,000 yes/no questions from Google search logs paired with Wikipedia passages that contain the answers, then tested a range of pre-training sources followed by fine-tuning on their data. They compared entailment corpora, extractive and multiple-choice QA sets, paraphrase data, and strong unsupervised language models including BERT.
The key findings are that natural yes/no questions demand diverse inference types, with fewer than 40 percent solvable by paraphrase detection alone; pre-training on the MultiNLI entailment corpus produces the strongest single supervised transfer result; combining MultiNLI pre-training with BERT yields the highest accuracy of 80.4 percent; and this figure remains well below the 90 percent human performance level.
These results indicate that even large-scale unsupervised pre-training leaves substantial headroom on inference-heavy yes/no questions drawn from real usage, and that high-quality labeled entailment data supplies complementary signal that improves final performance.
The authors recommend that future modeling efforts incorporate entailment pre-training when targeting yes/no QA and suggest extending the task to full-document settings to increase realism.
The main limitations are the modest dataset size relative to other QA benchmarks and the restriction to single passages rather than entire documents; the reported gains are consistent across multiple runs but still rest on Wikipedia text and English-language questions only.
- Paper: A Broad-Coverage Challenge Corpus for Sentence Understanding through Inference, Adina Williams et al. (2016). Introduces the MultiNLI dataset that serves as the crucial intermediate supervised pre-training corpus for BoolQ's primary transfer learning findings.
- Paper: BERT: Pre-training of Deep Bidirectional Transformers for Language Understanding, Jacob Devlin et al. (2019). Presents the foundational pre-trained Transformer architecture (BERT) that BoolQ fine-tunes and evaluates to demonstrate state-of-the-art performance on yes/no comprehension.
- Paper: SQuAD: 100,000+ Questions for Machine Comprehension of Text, Pranav Rajpurkar et al. (2016). Establishes the standard extractive question-answering benchmark paradigm that BoolQ directly builds upon and contrasts with natural inference-heavy yes/no queries.
- Paper: Improving Language Understanding by Generative Pre-Training, Alec Radford et al. (2018). Introduces generative pre-training and task-agnostic fine-tuning methodologies that underpin BoolQ's investigation into transfer learning across diverse natural language understanding tasks.
- Paper: Supervised Learning of Universal Sentence Representations from Natural Language Inference Data, Alexis Conneau et al. (2017). Demonstrates the power of using natural language inference datasets for transfer learning to downstream tasks, providing the conceptual groundwork for BoolQ's cross-task transfer experiments.
- Paper: HotpotQA: A Dataset for Diverse, Explainable Multi-hop Question Answering, Zhilin Yang et al. (2018). Pioneers multi-hop, inference-driven question answering benchmarks from Wikipedia, establishing the challenge of complex passage reasoning that BoolQ adapts for binary question formats.
- Paper: Know What You Don't Know: Unanswerable Questions for SQuAD, Pranav Rajpurkar et al. (2018). Highlights the critical limitations of shallow pattern-matching in reading comprehension systems, motivating BoolQ's exploration of challenging inferential queries.
- Paper: Exploring the Limits of Transfer Learning with a Unified Text-to-Text Transformer, Colin Raffel et al. (2020). Integrates BoolQ into the SuperGLUE benchmark to evaluate unified text-to-text language models on complex comprehension tasks.
- Paper: RoBERTa: A Robustly Optimized BERT Pretraining Approach, Yinhan Liu et al. (2019). Demonstrates how enhanced pre-training optimization recipes substantially push performance bounds on reading comprehension benchmarks including BoolQ.
- Paper: Language Models are Few-Shot Learners, T. B. Brown et al. (2020). Evaluates BoolQ within an extensive suite of tasks to measure zero-shot and few-shot reasoning capabilities across scale.
- Paper: BART: Denoising Sequence-to-Sequence Pre-training for Natural Language Generation, Translation, and Comprehension, Mike Lewis et al. (2020). Applies a denoising sequence-to-sequence model to natural language comprehension and inference benchmarks established by earlier question-answering studies.
- Paper: Dense Passage Retrieval for Open-Domain Question Answering, Vladimir Karpukhin et al. (2020). Extends passage-level question answering to full-corpus open-domain retrieval using dense vector representations.
- Paper: Retrieval-Augmented Generation for Knowledge-Intensive NLP Tasks, Patrick Lewis et al. (2020). Builds end-to-end architectures combining dense passage retrieval with generative sequence models for knowledge-intensive question answering.
- Paper: Leveraging Passage Retrieval with Generative Models for Open Domain Question Answering, Gautier Izacard et al. (2021). Pushes open-domain question answering further by using generative reader-decoder models across multiple retrieved passages.
