papers

Publications (38)

cs.CL2025

Command A: An Enterprise-Ready Large Language Model

Team Cohere, :, Aakanksha +227

In this report we describe the development of Command A, a powerful large language model purpose-built to excel at real-world enterprise use cases. Command A is an agent-optimised…

cs.CL2022

Autoregressive Search Engines: Generating Substrings as Document Identifiers

Michele Bevilacqua, Giuseppe Ottaviano, Patrick Lewis +3

Knowledge-intensive language tasks require NLP systems to both provide the correct answer and retrieve supporting evidence for it in a given corpus. Autoregressive language models…

cs.CL2021

PAQ: 65 Million Probably-Asked Questions and What You Can Do With Them

Patrick Lewis, Yuxiang Wu, Linqing Liu +5

Open-domain Question Answering models which directly leverage question-answer (QA) pairs, such as closed-book QA (CBQA) models and QA-pair retrievers, show promise in terms of spee…

cs.CL2024

From One to Many: Expanding the Scope of Toxicity Mitigation in Language Models

Luiza Pozzobon, Patrick Lewis, Sara Hooker +1

To date, toxicity mitigation in language models has almost entirely been focused on single-language settings. As language models embrace multilingual capabilities, it's crucial our…

cs.CL2018

Interpretation of Natural Language Rules in Conversational Machine Reading

Marzieh Saeidi, Max Bartolo, Patrick Lewis +5

Most work in machine reading focuses on question answering problems where the answer is directly expressed in the text to read. However, many real-world question answering problems…

cs.CL2020

MLQA: Evaluating Cross-lingual Extractive Question Answering

Patrick Lewis, Barlas Oğuz, Ruty Rinott +2

Question answering (QA) models have shown rapid progress enabled by the availability of large, high-quality benchmark datasets. Such annotated datasets are difficult and costly to…

cs.CL2022

The Web Is Your Oyster - Knowledge-Intensive NLP against a Very Large Web Corpus

Aleksandra Piktus, Fabio Petroni, Vladimir Karpukhin +8

In order to address increasing demands of real-world applications, the research for knowledge-intensive NLP (KI-NLP) should advance by capturing the challenges of a truly open-doma…

cs.IR2022

Reasoning over Public and Private Data in Retrieval-Based Systems

Simran Arora, Patrick Lewis, Angela Fan +2

Users and organizations are generating ever-increasing amounts of private data from a wide range of sources. Incorporating private data is important to personalize open-domain appl…

cs.AI2023

Goodtriever: Adaptive Toxicity Mitigation with Retrieval-augmented Models

Luiza Pozzobon, Beyza Ermis, Patrick Lewis +1

Considerable effort has been dedicated to mitigating toxicity, but existing methods often require drastic modifications to model parameters or the use of computationally intensive…

cs.CL2023

Mini-Model Adaptation: Efficiently Extending Pretrained Models to New Languages via Aligned Shallow Training

Kelly Marchisio, Patrick Lewis, Yihong Chen +1

Prior work shows that it is possible to expand pretrained Masked Language Models (MLMs) to new languages by learning a new set of embeddings, while keeping the transformer body fro…

cs.CL2022

EditEval: An Instruction-Based Benchmark for Text Improvements

Jane Dwivedi-Yu, Timo Schick, Zhengbao Jiang +6

Evaluation of text generation to date has primarily focused on content created sequentially, rather than improvements on a piece of text. Writing, however, is naturally an iterativ…

cs.CL2021

KILT: a Benchmark for Knowledge Intensive Language Tasks

Fabio Petroni, Aleksandra Piktus, Angela Fan +10

Challenging problems such as open-domain question answering, fact checking, slot filling and entity linking require access to large, external knowledge sources. While some models d…

cs.CL2020

Dense Passage Retrieval for Open-Domain Question Answering

Vladimir Karpukhin, Barlas Oğuz, Sewon Min +5

Open-domain question answering relies on efficient passage retrieval to select candidate contexts, where traditional sparse vector space models, such as TF-IDF or BM25, are the de…

cs.CL2024

MultiContrievers: Analysis of Dense Retrieval Representations

Seraphina Goldfarb-Tarrant, Pedro Rodriguez, Jane Dwivedi-Yu +1

Dense retrievers compress source documents into (possibly lossy) vector representations, yet there is little analysis of what information is lost versus preserved, and how it affec…

cs.CL2022

Challenges in Generalization in Open Domain Question Answering

Linqing Liu, Patrick Lewis, Sebastian Riedel +1

Recent work on Open Domain Question Answering has shown that there is a large discrepancy in model performance between novel test questions and those that largely overlap with trai…

cs.CL2021

Answering Complex Open-Domain Questions with Multi-Hop Dense Retrieval

Wenhan Xiong, Xiang Lorraine Li, Srini Iyer +8

We propose a simple and efficient multi-hop dense retrieval approach for answering complex open-domain questions, which achieves state-of-the-art performance on two multi-hop datas…

cs.CL2022

Atlas: Few-shot Learning with Retrieval Augmented Language Models

Gautier Izacard, Patrick Lewis, Maria Lomeli +7

Large language models have shown impressive few-shot results on a wide range of tasks. However, when knowledge is key for such results, as is the case for tasks such as question an…

cs.CL2023

On the Challenges of Using Black-Box APIs for Toxicity Evaluation in Research

Luiza Pozzobon, Beyza Ermis, Patrick Lewis +1

Perception of toxicity evolves over time and often differs between geographies and cultural backgrounds. Similarly, black-box commercially available APIs for detecting toxicity, su…

cs.IR2022

Improving Wikipedia Verifiability with AI

Fabio Petroni, Samuel Broscheit, Aleksandra Piktus +10

Verifiability is a core content policy of Wikipedia: claims that are likely to be challenged need to be backed by citations. There are millions of articles available online and tho…

cs.CL2021

Boosted Dense Retriever

Patrick Lewis, Barlas Oğuz, Wenhan Xiong +3

We propose DrBoost, a dense retrieval ensemble inspired by boosting. DrBoost is trained in stages: each component model is learned sequentially and specialized by focusing only on…

cs.CL2021

Domain-matched Pre-training Tasks for Dense Retrieval

Barlas Oğuz, Kushal Lakhotia, Anchit Gupta +8

Pre-training on larger datasets with ever increasing model size is now a proven recipe for increased performance across almost all NLP tasks. A notable exception is information ret…

cs.AI2025

FLARE: Faithful Logic-Aided Reasoning and Exploration

Erik Arakelyan, Pasquale Minervini, Pat Verga +2

Modern Question Answering (QA) and Reasoning approaches based on Large Language Models (LLMs) commonly use prompting techniques, such as Chain-of-Thought (CoT), assuming the result…

cs.CL2021

Retrieval-Augmented Generation for Knowledge-Intensive NLP Tasks

Patrick Lewis, Ethan Perez, Aleksandra Piktus +9

Large pre-trained language models have been shown to store factual knowledge in their parameters, and achieve state-of-the-art results when fine-tuned on downstream NLP tasks. Howe…

cs.CL2022

Salient Phrase Aware Dense Retrieval: Can a Dense Retriever Imitate a Sparse One?

Xilun Chen, Kushal Lakhotia, Barlas Oğuz +6

Despite their recent popularity and well-known advantages, dense retrievers still lag behind sparse methods such as BM25 in their ability to reliably match salient phrases and rare…

cs.CL2021

A Few More Examples May Be Worth Billions of Parameters

Yuval Kirstain, Patrick Lewis, Sebastian Riedel +1

We investigate the dynamics of increasing the number of model parameters versus the number of labeled examples across a wide variety of tasks. Our exploration reveals that while sc…

cs.CL2021

NeurIPS 2020 EfficientQA Competition: Systems, Analyses and Lessons Learned

Sewon Min, Jordan Boyd-Graber, Chris Alberti +50

We review the EfficientQA competition from NeurIPS 2020. The competition focused on open-domain question answering (QA), where systems take natural language questions as input and…

cs.CL2020

Question and Answer Test-Train Overlap in Open-Domain Question Answering Datasets

Patrick Lewis, Pontus Stenetorp, Sebastian Riedel

Ideally Open-Domain Question Answering models should exhibit a number of competencies, ranging from simply memorizing questions seen at training time, to answering novel question f…

cs.CL2024

ALR: A Retrieve-then-Reason Framework for Long-context Question Answering

Huayang Li, Pat Verga, Priyanka Sen +5

The context window of large language models (LLMs) has been extended significantly in recent years. However, while the context length that the LLM can process has grown, the capabi…

cs.CL2020

Unsupervised Question Decomposition for Question Answering

Ethan Perez, Patrick Lewis, Wen-tau Yih +2

We aim to improve question answering (QA) by decomposing hard questions into simpler sub-questions that existing QA systems are capable of answering. Since labeling questions with…

cs.CL2022

PEER: A Collaborative Language Model

Timo Schick, Jane Dwivedi-Yu, Zhengbao Jiang +7

Textual content is often the output of a collaborative writing process: We start with an initial draft, ask for suggestions, and repeatedly make changes. Agnostic of this process,…

cs.CL2019

Unsupervised Question Answering by Cloze Translation

Patrick Lewis, Ludovic Denoyer, Sebastian Riedel

Obtaining training data for Question Answering (QA) is time-consuming and resource-intensive, and existing QA datasets are only available for limited domains and languages. In this…

cs.CL2020

How Context Affects Language Models' Factual Predictions

Fabio Petroni, Patrick Lewis, Aleksandra Piktus +4

When pre-trained on large unsupervised textual corpora, language models are able to store and retrieve factual knowledge to some extent, making it possible to use them directly for…

cs.CL2024

Replacing Judges with Juries: Evaluating LLM Generations with a Panel of Diverse Models

Pat Verga, Sebastian Hofstatter, Sophia Althammer +6

As Large Language Models (LLMs) have become more advanced, they have outpaced our abilities to accurately evaluate their quality. Not only is finding data to adequately probe parti…

cs.CL2024

SnapKV: LLM Knows What You are Looking for Before Generation

Yuhong Li, Yingbing Huang, Bowen Yang +6

Large Language Models (LLMs) have made remarkable progress in processing extensive contexts, with the Key-Value (KV) cache playing a vital role in enhancing their performance. Howe…

cs.CL2023

Rank-without-GPT: Building GPT-Independent Listwise Rerankers on Open-Source Large Language Models

Xinyu Zhang, Sebastian Hofstätter, Patrick Lewis +2

Listwise rerankers based on large language models (LLM) are the zero-shot state-of-the-art. However, current works in this direction all depend on the GPT models, making it a singl…

cs.AI2026

Counsel: A Meta-Evaluation Dataset for Agentic Tasks

Sashank Pisupati, Henry Broomfield, Eujeong Choi +5

As agentic systems tackle increasingly complex multi-step tasks, evaluating their trajectories presents a major bottleneck - human annotation of a single trajectory on popular agen…

cs.CL2022

Task-aware Retrieval with Instructions

Akari Asai, Timo Schick, Patrick Lewis +5

We study the problem of retrieval with instructions, where users of a retrieval system explicitly describe their intent along with their queries. We aim to develop a general-purpos…

cs.CL2019

Language Models as Knowledge Bases?

Fabio Petroni, Tim Rocktäschel, Patrick Lewis +4

Recent progress in pretraining language models on large textual corpora led to a surge of improvements for downstream NLP tasks. Whilst learning linguistic knowledge, these models…