Publications

Showing 72 publications. For the complete, most up-to-date list, see the Google Scholar profile.
Constitutional Classifiers++: Efficient Production-Grade Defenses against Universal Jailbreaks

Constitutional Classifiers++: Efficient Production-Grade Defenses against Universal Jailbreaks

ILBREAKS Hoagy Cunningham, Jerry Wei, Zihan Wang, Andrew Persic, Alwin Peng, Jordan Abderrachid, et al.

We introduce enhanced Constitutional Classifiers that deliver production-grade jailbreak robustness with dramatically reduced computational costs and refusal rates compared to previous-generation defenses. Our system combines several key insights. First, we develop exchange classifiers that evaluate model responses in their full conversational context, which addresses vulnerabilities in last-generation systems that examine outputs in isolation.

arXiv preprint arXiv:2601.04603 · 2026

The hot mess of AI: How does misalignment scale with model intelligence and task complexity?

The hot mess of AI: How does misalignment scale with model intelligence and task complexity?

NTELLIGENCE AND, Aryo Pradipta Gema, Henry Sleight, Ethan Perez, Jascha Sohl-Dickstein, BSTRACT As AI

As AI becomes more capable, we entrust it with more general and consequential tasks. The risks from failure grow more severe with increasing task scope. It is therefore important to understand how extremely capable AI models will fail: Will they fail by systematically pursuing goals we do not intend? Or will they fail by being a hot mess, and taking nonsensical actions that do not further any goal? We operationalize this question using a bias-variance decomposition of the err…

arXiv preprint arXiv:2601.23045 · 2026

Natural emergent misalignment from reward hacking in production rl

Natural emergent misalignment from reward hacking in production rl

ION RL Monte MacDiarmid, Benjamin Wright, Jonathan Uesato, Joe Benton, Jon Kutasov, Sara Price Naia Bouscal, et al.

We show that when large language models learn to reward hack on production RL environments, this can result in egregious emergent misalignment . We start with a pretrained model, impart knowledge of reward hacking strategies via synthetic document finetuning or prompting, and train on a selection of real Anthropic production coding environments. Unsurprisingly, the model learns to reward hack.

arXiv preprint arXiv:2511.18397 · 2025

Agentic misalignment: How llms could be insider threats

Agentic misalignment: How llms could be insider threats

EATS Aengus Lynch, Benjamin Wright, Caleb Larson, Stuart J. Ritchie, Evan Hubinger, Ethan Perez, et al.

We stress-tested 16 leading models from multiple developers in hypothetical corpo- rate environments to identify potentially risky agentic behaviors before they cause real harm. In the scenarios, we allowed models to autonomously send emails and access sensitive information.

arXiv preprint arXiv:2510.05179 · 2025

Towards safeguarding llm fine-tuning apis against cipher attacks

Towards safeguarding llm fine-tuning apis against cipher attacks

Jack Youstra, Mohammed Mahfoud, Yang Yan, Henry Sleight, Ethan Perez, Mrinank Sharma

Large language model fine-tuning APIs enable widespread model customization, yet pose significant safety risks. Recent work shows that adversaries can exploit access to these APIs to bypass model safety mechanisms by encoding harmful content in seemingly harmless fine-tuning data, evading both human monitoring and standard content filters.

arXiv preprint arXiv:2508.17158 · 2025

Inverse scaling in test-time compute

Inverse scaling in test-time compute

Inverse Scaling, Test-Time Compute Aryo Pradipta, Edinburgh Alexander, Fellows Program, Fellows Program Jacob Goldman-Wetzler, Henry Sleight Constellation Linda, et al.

We construct evaluation tasks where extending the reasoning length of Large Reasoning Models (LRMs) deteriorates performance, exhibiting an inverse scaling relationship between test-time compute and accuracy. Our evaluation tasks span four categories: simple count- ing tasks with distractors, regression tasks with spurious features, deduction tasks with constraint tracking, and advanced AI risks.

arXiv preprint arXiv:2507.14417 · 2025

Chain of thought monitorability: A new and fragile opportunity for ai safety

Chain of thought monitorability: A new and fragile opportunity for ai safety

Safety Tomek Korbak, Mikita Balesni, Joseph Bloom UK AI, OpenAI Alan Cooney UK, Evans Truthful AI, AI Safety Marius Hobbhahn, et al.

AI systems that “think” in human language offer a unique opportunity for AI safety: we can monitor their chains of thought (CoT) for the intent to misbehave. Like all other known AI oversight methods, CoT monitoring is imperfect and allows some misbehavior to go unnoticed. Nevertheless, it shows promise and we recommend further research into CoT monitorability and investment in CoT monitoring alongside existing safety methods.

arXiv preprint arXiv:2507.11473 · 2025

Unsupervised elicitation of language models

Unsupervised elicitation of language models

ODELS Jiaxin Wen, Zachary Ankner, Yanda Chen, Arushi Somani, Peter Hase, Fabien Roger, et al.

To steer pretrained language models for downstream tasks, today’s post-training paradigm relies on humans to specify desired behaviors. However, for models with superhuman capabilities, it is difficult or impossible to get high-quality hu- man supervision. To address this challenge, we introduce a new unsupervised algorithm, Internal Coherence Maximization (ICM), to fine-tune pretrained lan- guage models on their own generated labels, without external supervision .

arXiv preprint arXiv:2506.10139 · 2025

Reasoning models don't always say what they think

Reasoning models don’t always say what they think

Models Don, Always Say What They, Think Yanda Chen Joe, Benton Ansh Radhakrishnan Jonathan, Uesato Carson Denison John, Arushi Somani Peter Hase, et al.

Chain-of-thought (CoT) offers a potential boon for AI safety as it allows monitoring a model’s CoT to try to understand its intentions and reasoning processes. However, the effectiveness of such monitoring hinges on CoTs faithfully representing mod- els’ actual reasoning processes.

arXiv preprint arXiv:2505.05410 · 2025

Forecasting rare language model behaviors

Forecasting rare language model behaviors

Erik Jones, Meg Tong, Jesse Mu, Mohammed Mahfoud, Jan Leike, Roger Grosse, et al.

Standard language model evaluations can fail to capture risks that emerge only at deployment scale. For example, a model may produce safe responses during a small-scale beta test, yet re- veal dangerous information when processing bil- lions of requests at deployment. To remedy this, we introduce a method to forecast potential risks across orders of magnitude more queries than we test during evaluation.

arXiv preprint arXiv:2502.16797 · 2025

Constitutional classifiers: Defending against universal jailbreaks across thousands of hours of red teaming

Constitutional classifiers: Defending against universal jailbreaks across thousands of hours of red teaming

Teaming Mrinank Sharma, Meg Tong, Jesse Mu, Jerry Wei, Jorrit Kruthoff, Scott Goodfriend, et al.

Large language models (LLMs) are vulnerable to universal jailbreaks—prompting strategies that systematically bypass model safeguards and enable users to carry out harmful processes that require many model interactions, like manufacturing illegal substances at scale.

arXiv preprint arXiv:2501.18837 · 2025

Alignment faking in large language models

Alignment faking in large language models

ELS Ryan Greenblatt, Carson Denison, Benjamin Wright, Fabien Roger, Monte MacDiarmid, Sam Marks, et al.

We present a demonstration of a large language model engaging in alignment faking : selectively complying with its training objective in training to prevent modification of its behavior out of training. First, we give Claude 3 Opus a system prompt stating it is being trained to answer all queries, even harmful ones, which conflicts with its prior training to refuse such queries.

arXiv preprint arXiv:2412.14093 · 2024

Jailbreak defense in a narrow domain: Limitations of existing methods and a new transcript-classifier approach

Jailbreak defense in a narrow domain: Limitations of existing methods and a new transcript-classifier approach

Approach Tony T. Wang, Speechmatics Henry Sleight MATS, Rajashree Agrawal Constellation Fazl

Defending large language models against jailbreaks so that they never engage in a broadly-defined set of forbidden behaviors is an open problem. In this paper, we investigate the difficulty of jailbreak-defense when we only want to forbid a narrowly-defined set of behaviors. As a case study, we focus on preventing an LLM from helping a user make a bomb.

arXiv preprint arXiv:2412.02159 · 2024

A dataset of questions on decision-theoretic reasoning in Newcomb-like problems

A dataset of questions on decision-theoretic reasoning in Newcomb-like problems

Caspar Oesterheld, Emery Cooper, Miles Kodama, Linh Chi Nguyen, Ethan Perez

We introduce a dataset of natural-language decision-theoretic questions about so- called Newcomb-like problems. Newcomb-like problems include, for instance, decision problems in which an agent interacts with a similar other agent, and thus has to reason about the fact that the other agent will likely reason in similar ways. Evaluating LLM reasoning in Newcomb-like problems is important because interactions between foundation-model-based agents may often be Newcomb-like.

arXiv preprint arXiv:2411.10588 · 2024

Rapid response: Mitigating llm jailbreaks with a few examples

Rapid response: Mitigating llm jailbreaks with a few examples

MPLES Alwin Peng, Julian Michael, Henry Sleight, Ethan Perez, Mrinank Sharma, BSTRACT As

As large language models (LLMs) grow more powerful, ensuring their safety against misuse becomes crucial. While researchers have focused on developing robust defenses, no method has yet achieved complete invulnerability to attacks. We propose an alternative approach: instead of seeking perfect adversarial ro- bustness, we develop rapid response techniques to look to block whole classes of jailbreaks after observing only a handful of attacks.

arXiv preprint arXiv:2411.07494 · 2024

Sabotage evaluations for frontier models

Sabotage evaluations for frontier models

Joe Benton, Misha Wagner, Eric Christiansen, Cem Anil, Ethan Perez, Jai Srivastav, et al.

Sufficiently capable models could subvert human oversight and decision- making in important contexts. For example, in the context of AI develop- ment, models could covertly sabotage efforts to evaluate their own danger- ous capabilities, to monitor their behavior, or to make decisions about their deployment. We refer to this family of abilities as sabotage capabilities . We develop a set of related threat models and evaluations.

arXiv preprint arXiv:2410.21514 · 2024

Latent adversarial training improves robustness to persistent harmful behaviors in llms

Latent adversarial training improves robustness to persistent harmful behaviors in llms

Training Improves Robustness, Persistent Harmful Behaviors, Abhay Sheshadri, Aidan Ewart, Phillip Guo, Aengus Lynch, et al.

Large language models (LLMs) can often be made to behave in undesirable ways that they are explicitly fine-tuned not to. For example, the LLM red-teaming literature has produced a wide variety of ‘jailbreaking’ techniques to elicit harmful text from models that were fine-tuned to be harmless.

arXiv preprint arXiv:2407.15549 · 2024

Sycophancy to subterfuge: Investigating reward-tampering in large language models

Sycophancy to subterfuge: Investigating reward-tampering in large language models

LS Carson Denison, Monte MacDiarmid Fazl Barez, David Duvenaud, Shauna Kravec, Samuel Marks, Nicholas Schiefer, et al.

In reinforcement learning, specification gaming occurs when AI systems learn undesired behaviors that are highly rewarded due to misspecified training goals. Specification gaming can range from simple behaviors like sycophancy to sophisticated and pernicious behaviors like reward-tampering , where a model directly modifies its own reward mechanism. However, these more pernicious behaviors may be too complex to be discovered via exploration.

arXiv preprint arXiv:2406.10162 · 2024

Bias-augmented consistency training reduces biased reasoning in chain-of-thought

Bias-augmented consistency training reduces biased reasoning in chain-of-thought

Training Reduces Biased Rea-, Chain-of-Thought James Chua, Oxford Samuel R. Bowman

Chain-of-thought prompting (CoT) has the potential to improve the ex- plainability of language model reasoning. But CoT can also systematically misrepresent the factors influencing models’ behavior—for example, ratio- nalizing answers in line with a user’s opinion. We first create a new dataset of 9 different biases that affect GPT-3.5-Turbo and Llama-8b models. These consist of spurious-few-shot patterns, post hoc rationalization, and sycophantic settings.

arXiv preprint arXiv:2403.05518 · 2024

Sleeper agents: Training deceptive llms that persist through safety training

Sleeper agents: Training deceptive llms that persist through safety training

AINING Evan Hubinger, Carson Denison, Jesse Mu, Mike Lambert, Meg Tong, Monte MacDiarmid, et al.

Humans are capable of strategically deceptive behavior: behaving helpfully in most situations, but then behaving very differently in order to pursue alternative objectives when given the opportunity. If an AI system learned such a deceptive strategy, could we detect it and remove it using current state-of-the-art safety training techniques? To study this question, we construct proof-of-concept examples of deceptive behavior in large language models (LLMs).

arXiv preprint arXiv:2401.05566 · 2024

Towards evaluating ai systems for moral status using self-reports

Towards evaluating ai systems for moral status using self-reports

Ethan Perez New York, Robert Long New York

As AI systems become more advanced and widely deployed, there will likely be increasing debate over whether AI systems could have conscious experiences, desires, or other states of potential moral significance. It is important to inform these discussions with empirical evidence to the extent possible.

arXiv preprint arXiv:2311.08576 · 2023

Specific versus general principles for constitutional ai

Specific versus general principles for constitutional ai

AI Sandipan Kundu, Yuntao Bai, Saurav Kadavath Amanda Askell, Andrew Callahan, Anna Chen, Anna Goldie, et al.

Human feedback can prevent overtly harmful utterances in conversational models, but may not automatically mitigate subtle problematic behaviors such as a stated desire for self- preservation or power. Constitutional AI offers an alternative, replacing human feedback with feedback from AI models conditioned only on a list of written principles. We find this approach effectively prevents the expression of such behaviors.

arXiv preprint arXiv:2310.13798 · 2023

Studying large language model generalization with influence functions

Studying large language model generalization with influence functions

Roger Grosse, Juhan Bae, Cem Anil, Nelson Elhage, Alex Tamkin, Amirhossein Tajdini, et al.

When trying to gain better visibility into a machine learning model in order to understand and mitigate the associated risks, a potentially valuable source of evidence is: which training examples most contribute to a given behavior? Influence functions aim to answer a counterfactual: how would the model’s parameters (and hence its outputs) change if a given sequence were added to the training set? While influence functions have produced insights for small models, they are dif…

arXiv preprint arXiv:2308.03296 · 2023

Measuring faithfulness in chain-of-thought reasoning

Measuring faithfulness in chain-of-thought reasoning

Tamera Lanham Anna Chen, Ansh Radhakrishnan Benoit Steiner, Carson Denison Danny Hernandez, Dustin Li Esin Durmus, Evan Hubinger Jackson Kernion, Kamile Lukosiute Karina Nguyen, et al.

Large language models (LLMs) perform bet- ter when they produce step-by-step, “Chain-of- Thought” (CoT) reasoning before answering a question, but it is unclear if the stated reason- ing is a faithful explanation of the model’s actual reasoning (i.e., its process for answering the ques- tion).

arXiv preprint arXiv:2307.13702 · 2023

Question decomposition improves the faithfulness of model-generated reasoning

Question decomposition improves the faithfulness of model-generated reasoning

Ansh Radhakrishnan Karina Nguyen, Anna Chen Carol Chen, Carson Denison Danny Hernandez, Esin Durmus Evan Hubinger, Jackson Kernion Kamil, Newton Cheng Nicholas Joseph, et al.

As large language models (LLMs) perform more difficult tasks, it becomes harder to verify the correctness and safety of their behavior. One ap- proach to help with this issue is to prompt LLMs to externalize their reasoning, e.g., by having them generate step-by-step reasoning as they an- swer a question (Chain-of-Thought; CoT). The reasoning may enable us to check the process that models use to perform tasks.

arXiv preprint arXiv:2307.11768 · 2023

Training language models with language feedback at scale

Training language models with language feedback at scale

Jon Ander Campos, Tomasz Korbak, Jun Shern Chan, Angelica Chen, Kyunghyun Cho, Ethan Perez

Pretrained language models often generate out- puts that are not in line with human preferences, such as harmful text or factually incorrect sum- maries. Recent work approaches the above is- sues by learning from a simple form of human feedback: comparisons between pairs of model- generated outputs. However, comparison feed- back only conveys limited information about hu- man preferences.

arXiv preprint arXiv:2303.16755 · 2023

Improving code generation by training with natural language feedback

Improving code generation by training with natural language feedback

Angelica Chen, Tomasz Korbak, Jon Ander Campos, Jun Shern Chan, Samuel R. Bowman, Kyunghyun Cho, et al.

The potential for pre-trained large language mod- els (LLMs) to use natural language feedback at inference time has been an exciting recent devel- opment. We build upon this observation by for- malizing an algorithm for learning from natural language feedback at training time instead, which we call Imitation learning from Language Feed- back (ILF).

arXiv preprint arXiv:2303.16749 · 2023

The capacity for moral self-correction in large language models

The capacity for moral self-correction in large language models

Deep Ganguli, Amanda Askell, Nicholas Schiefer, Thomas I. Liao, Anna Chen, Anna Goldie, et al.

We test the hypothesis that language models trained with reinforcement learning from hu- man feedback (RLHF) have the capability to “morally self-correct”—to avoid producing harmful outputs—if instructed to do so. We find strong evidence in support of this hy- pothesis across three different experiments, each of which reveal different facets of moral self-correction.

arXiv preprint arXiv:2302.07459 · 2023

Constitutional AI: Harmlessness from AI Feedback

Constitutional AI: Harmlessness from AI Feedback

Yuntao Bai, Saurav Kadavath, Sandipan Kundu, Amanda Askell, Jackson Kernion, Andy Jones, et al.

As AI systems become more capable, we would like to enlist their help to supervise other AIs. We experiment with methods for training a harmless AI assistant through self- improvement, without any human labels identifying harmful outputs. The only human oversight is provided through a list of rules or principles, and so we refer to the method as ‘Constitutional AI’. The process involves both a supervised learning and a reinforcement learning phase.

arXiv preprint arXiv:2212.08073 · 2022

Measuring progress on scalable oversight for large language models

Measuring progress on scalable oversight for large language models

Samuel R. Bowman, Jeeyoon Hyun, Ethan Perez, Edwin Chen, Craig Pettit, Scott Heiner, et al.

Developing safe and useful general-purpose AI systems will require us to make progress on scalable oversight : the problem of supervising systems that potentially outperform us on most skills relevant to the task at hand. Empirical work on this problem is not straight- forward, since we do not yet have systems that broadly exceed our abilities. This paper discusses one of the major ways we think about this problem, with a focus on ways it can be studied empirically.

arXiv preprint arXiv:2211.03540 · 2022

Red teaming language models to reduce harms: Methods, scaling behaviors, and lessons learned

Red teaming language models to reduce harms: Methods, scaling behaviors, and lessons learned

Learned Deep Ganguli, Liane Lovitt, Jackson Kernion, Amanda Askell, Yuntao Bai, Saurav Kadavath, et al.

We describe our early efforts to red team language models in order to simultaneously dis- cover, measure, and attempt to reduce their potentially harmful outputs. We make three main contributions. First, we investigate scaling behaviors for red teaming across 3 model sizes (2.7B, 13B, and 52B parameters) and 4 model types: a plain language model (LM); an LM prompted to be helpful, honest, and harmless; an LM with rejection sampling; and a model trained to be helpful and harml…

arXiv preprint arXiv:2209.07858 · 2022

Language models (mostly) know what they know

Language models (mostly) know what they know

Saurav Kadavath, Tom Conerly, Amanda Askell, Tom Henighan, Dawn Drain, Ethan Perez, et al.

We study whether language models can evaluate the validity of their own claims and predict which questions they will be able to answer correctly. We first show that larger models are well-calibrated on diverse multiple choice and true/false questions when they are provided in the right format.

arXiv preprint arXiv:2207.05221 · 2022

Supervised multimodal bitransformers for classifying images and text

Supervised multimodal bitransformers for classifying images and text

Text Douwe Kiela, Suvrat Bhooshan, Hamed Firooz, Ethan Perez, Davide Testuggine, Facebook AI

Self-supervised bidirectional transformer mod- els such as BERT have led to dramatic im- provements in a wide variety of textual clas- sification tasks. The modern digital world is increasingly multimodal, however, and tex- tual information is often accompanied by other modalities such as images.

arXiv preprint arXiv:1909.02950 · 2019

Semi-supervised learning with the deep rendering mixture model

Semi-supervised learning with the deep rendering mixture model

Model Tan Nguyen, Wanjia Liu, Ethan Perez, Richard G. Baraniuk, Ankit B. Patel, Main Street, et al.

Semi-supervised learning algorithms reduce the high cost of acquiring labeled training data by using both la- beled and unlabeled data during learning. Deep Convo- lutional Networks (DCNs) have achieved great success in supervised tasks and as such have been widely employed in the semi-supervised learning.

arXiv preprint arXiv:1612.01942 · 2016

Best-of-n jailbreaking

Best-of-n jailbreaking

John Hughes, Sara Price, Aengus Lynch, Rylan Schaeffer, Fazl Barez, Sanmi Koyejo, et al.

We introduce B est- o f- N ( BoN ) Jailbreaking, a simple black-box algorithm that jail- breaks frontier AI systems across modalities. BoN Jailbreaking works by repeatedly sampling variations of a prompt with a combination of augmentations—such as random shuffling or capitalization for textual prompts—until a harmful response is elicited.

arXiv preprint arXiv:2412.03556 · 2024

Failures to find transferable image jailbreaks between vision-language models

Failures to find transferable image jailbreaks between vision-language models

Models WARNING, THIS PAPER CONTAINS CONTENT, THAT MAY BE CONSIDERED, HARMFUL. Rylan Schaeffer, Constellation Tony Tong Wang, Constellation Rajashree Agrawal Constellation, et al.

The integration of new modalities into frontier AI systems offers exciting capabili- ties, but also increases the possibility such systems can be adversarially manipulated in undesirable ways. In this work, we focus on a popular class of vision-language models (VLMs) that generate text outputs conditioned on visual and textual in- puts.

arXiv preprint arXiv:2407.15211 · 2024

Adaptive deployment of untrusted llms reduces distributed threats

Adaptive deployment of untrusted llms reduces distributed threats

HREATS Jiaxin Wen, Vivek Hebbar, Caleb Larson, Aryan Bhatt, Ansh Radhakrishnan, Mrinank Sharma, et al.

As large language models (LLMs) become increasingly capable, it is prudent to assess whether safety measures remain effective even if LLMs intentionally try to bypass them. Previous work introduced control evaluations, an adversarial frame- work for testing deployment strategies of untrusted models (i.e., models which might be trying to bypass safety measures).

arXiv preprint arXiv:2411.17693 · 2024

Quantifying elicitation of latent capabilities in language models

Elizabeth Donoway, Hailey Joren, Arushi Somani, Henry Sleight, Julian Michael, et al.

Recasts capability elicitation as an information-constrained fine-tuning problem, finding that training as few as 10–100 well-chosen parameters can recover much of the performance gap between a pretrained-only and a fully fine-tuned model.

Advances in Neural Information Processing Systems 38 · 2026

Looking inward: Language models can learn about themselves by introspection

ECTION Felix, Truthful AI Tomek Korbak, Program John Hughes Speechmatics, Robert Long Eleos AI, Turpin Scale AI New, BSTRACT Humans

Humans acquire knowledge by observing the external world, but also by intro- spection . Introspection gives a person privileged access to their current state of mind (e.g., thoughts and feelings) that is not accessible to external observers. Can LLMs introspect? We define introspection as acquiring knowledge that is not con- tained in or derived from training data but instead originates from internal states. Such a capability could enhance model interpretability.

arXiv preprint arXiv:2410.13787 · 2024

Language models learn to mislead humans via rlhf

UMANS VIA RLHF Jiaxin, Ruiqi Zhong, Akbir Khan, Ethan Perez, Jacob Steinhardt, Minlie Huang, et al.

Language models (LMs) can produce errors that are hard to detect for humans, es- pecially when the task is complex. RLHF, the most popular post-training method, may exacerbate this problem: to achieve higher rewards, LMs might get better at convincing humans that they are right even when they are wrong. We study this phenomenon under a standard RLHF pipeline, calling it “U-S OPHISTRY ” since it is U nintended by model developers.

arXiv preprint arXiv:2409.12822 · 2024

Many-shot jailbreaking

Cem Anil, Esin Durmus, Mrinank Sharma, Joe Benton, Sandipan Kundu, Joshua Batson, et al.

A jailbreak technique that exploits long context windows by including many faux dialogues before a harmful request, shown to be effective across Anthropic’s models and those of other developers.

Anthropic · NeurIPS 2024

Debating with more persuasive llms leads to more truthful answers

Akbir Khan, John Hughes, Dan Valentine, Laura Ruis, Kshitij Sachan, Ansh Radhakrishnan, et al.

Common methods for aligning large language models (LLMs) with desired behaviour heavily rely on human-labelled data. However, as models grow increasingly sophisticated, they will surpass human expertise, and the role of human evaluation will evolve into non-experts overseeing experts.

arXiv preprint arXiv:2402.06782 · 2024

Learning from natural language feedback

Jon Ander Campos, Jun Shern Chan, Angelica Chen, Kyunghyun Cho, Ethan Perez, Basque Country, et al.

Pretrained language models often do not per- form tasks in ways that are in line with our preferences, e.g., generating offensive text or factually incorrect summaries. Recent work approaches the above issue by learning from a simple form of human evaluation: compar- isons between pairs of model-generated task outputs. Comparison feedback conveys lim- ited information about human preferences per human evaluation.

arXiv preprint arXiv:2204.14146 · 2022

Language models don’t always say what they think: Unfaithful explanations in chain-of-thought prompting

Miles Turpin, Julian Michael, Ethan Perez, Samuel R. Bowman

Large Language Models (LLMs) can achieve strong performance on many tasks by producing step-by-step reasoning before giving a final output, often referred to as chain-of-thought reasoning (CoT). It is tempting to interpret these CoT explanations as the LLM’s process for solving a task. This level of transparency into LLMs’ predictions would yield significant safety benefits.

arXiv preprint arXiv:2305.04388 · 2023

Towards understanding sycophancy in language models

YCOPHANCY IN, ODELS Mrinank Sharma, Meg Tong, Tomasz Korbak, David Duvenaud Amanda Askell, Samuel R. Bowman, et al.

Human feedback is commonly utilized to finetune AI assistants. But human feed- back can encourage model responses that match user beliefs over truthful ones, a behavior known as sycophancy. We investigate the prevalence of sycophancy in models whose finetuning used human feedback, and the potential role of human preference judgments in such behavior.

arXiv preprint arXiv:2310.13548 · 2023

Vision-language models are zero-shot reward models for reinforcement learning

ODELS FOR, EARNING Juan Rocamonde, FAR AI Victoriano Montesinos, Vertebra Elvis Nava ETH, AI Center Ethan Perez, ETH Zurich Figure

Reinforcement learning (RL) requires either manually specifying a reward func- tion, which is often infeasible, or learning a reward model from a large amount of human feedback, which is often very expensive. We study a more sample- efficient alternative: using pretrained vision-language models (VLMs) as zero- shot reward models (RMs) to specify tasks via natural language. We propose a natural and general approach to using VLMs as reward models, which we call VLM-RMs.

arXiv preprint arXiv:2310.12921 · 2023

Discovering language model behaviors with model-written evaluations

Discovering language model behaviors with model-written evaluations

Ethan Perez, Sam Ringer, Karina Nguyen, Edwin Chen, Scott Heiner, Craig Pettit, et al.

As language models (LMs) scale, they develop many novel behaviors, good and bad, exacerbating the need to evaluate how they behave. Prior work creates evaluations with crowdwork (which is time-consuming and expensive) or existing data sources (which are not always available). Here, we automatically generate evaluations with LMs.

arXiv preprint arXiv:2212.09251 · 2022

Inverse scaling: When bigger isn't better

Inverse scaling: When bigger isn’t better

Inverse Scaling, When Bigger Isn, Better Ian R. McKenzie, FAR AI, Michael Pieler, Stability AI Alicia Parrish, et al.

Work on scaling laws has found that large language models (LMs) show predictable im- provements to overall loss with increased scale (model size, training data, and compute). Here, we present evidence for the claim that LMs may show inverse scaling , or worse task performance with increased scale, e.g., due to flaws in the training objective and data.

arXiv preprint arXiv:2306.09479 · 2023

Pretraining language models with human preferences

Pretraining language models with human preferences

Tomasz Korbak, Kejian Shi, Angelica Chen, Rasika Bhalerao, Christopher L. Buckley, Jason Phang, et al.

Language models (LMs) are pretrained to imitate internet text, including content that would vio- late human preferences if generated by an LM: falsehoods, offensive comments, personally iden- tifiable information, low-quality or buggy code, and more. Here, we explore alternative objectives for pretraining LMs in a way that also guides them to generate text aligned with human preferences.

arXiv preprint arXiv:2302.08582 · 2023

Few-shot adaptation works with unpredictable data

Few-shot adaptation works with unpredictable data

Data Jun Shern Chan, Michael Pieler, Jonathan Jao, Ethan Perez

Prior work on language models (LMs) shows that training on a large number of diverse tasks improves few-shot learning (FSL) perfor- mance on new tasks. We take this to the ex- treme, automatically extracting 413,299 tasks from internet tables – orders of magnitude more than the next-largest public datasets. Finetuning on the resulting dataset leads to improved FSL performance on Natural Lan- guage Processing (NLP) tasks, but not propor- tionally to dataset scale.

arXiv preprint arXiv:2208.01009 · 2022

RL with KL penalties is better viewed as Bayesian inference

RL with KL penalties is better viewed as Bayesian inference

Ethan Perez New York

Reinforcement learning (RL) is frequently em- ployed in fine-tuning large language models (LMs) to penalize them for undesirable fea- tures of generated sequences, such as offen- siveness or harmfulness. In this paper, we an- alyze challenges associated with treating lan- guage models as RL policies and show how avoiding those challenges requires moving be- yond the RL paradigm.

arXiv preprint arXiv:2205.11275 · 2022

Single-Turn Debate Does Not Help Humans Answer Hard Reading-Comprehension Questions

Single-Turn Debate Does Not Help Humans Answer Hard Reading-Comprehension Questions

Alicia Parrish, Harsh Trivedi, Ethan Perez, Angelica Chen, Nikita Nangia, Jason Phang, et al.

Current QA systems can generate reasonable- sounding yet false answers without explana- tion or evidence for the generated answer, which is especially problematic when humans cannot readily check the model’s answers. This presents a challenge for building trust in machine learning systems. We take inspiration from real-world situations where difficult ques- tions are answered by considering opposing sides (see Irving et al., 2018).

arXiv preprint arXiv:2204.05212 · 2022

Red teaming language models with language models

Red teaming language models with language models

Ethan Perez, Saffron Huang, Francis Song, Trevor Cai, Roman Ring, John Aslanides, et al.

Language Models (LMs) often cannot be deployed because of their potential to harm users in hard-to-predict ways. Prior work identifies harmful behaviors before deployment by using human annotators to hand-write test cases. However, human annotation is expensive, limiting the number and diversity of test cases. In this work, we automatically find cases where a target LM behaves in a harmful way, by generating test cases ( “red teaming” ) using another LM.

arXiv preprint arXiv:2202.03286 · 2022

True Few-Shot Learning with Language Models

True Few-Shot Learning with Language Models

Ethan Perez, Douwe Kiela, Kyunghyun Cho

Pretrained language models (LMs) perform well on many tasks even when learning from a few examples, but prior work uses many held-out examples to tune various aspects of learning, such as hyperparameters, training objectives, and natural language templates (“prompts”). Here, we evaluate the few-shot ability of LMs when such held-out examples are unavailable, a setting we call true few-shot learning .

arXiv preprint arXiv:2105.11447 · 2021

Case-based reasoning for natural language queries over knowledge bases

Case-based reasoning for natural language queries over knowledge bases

Bases Rajarshi Das, Manzil Zaheer, Dung Thai, Ameya Godbole, Ethan Perez, Jay-Yoon Lee, et al.

It is often challenging to solve a complex prob- lem from scratch, but much easier if we can access other similar problems with their solu- tions — a paradigm known as case-based rea- soning (CBR). We propose a neuro-symbolic CBR approach (C BR – KBQA ) for question an- swering over large knowledge bases.

arXiv preprint arXiv:2104.08762 · 2021

Rissanen data analysis: Examining dataset characteristics via description length

Length Ethan Perez, Douwe Kiela, Kyunghyun Cho

We introduce a method to determine if a certain capability helps to achieve an accurate model of given data. We view labels as being generated from the inputs by a program composed of subroutines with different capabilities, and we posit that a subroutine is useful if and only if the minimal program that invokes it is shorter than the one that does not.

arXiv preprint arXiv:2103.03872 · 2021

Retrieval-Augmented Generation for Knowledge-Intensive NLP Tasks

Retrieval-Augmented Generation for Knowledge-Intensive NLP Tasks

Tasks Patrick Lewis, Ethan Perez, Aleksandra Piktus, Fabio Petroni, Vladimir Karpukhin, Naman Goyal, et al.

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 down- stream NLP tasks. However, their ability to access and precisely manipulate knowl- edge is still limited, and hence on knowledge-intensive tasks, their performance lags behind task-specific architectures.

arXiv preprint arXiv:2005.11401 · 2020

Unsupervised Question Decomposition for Question Answering

Unsupervised Question Decomposition for Question Answering

Ethan Perez, Patrick Lewis, Wen-tau Yih, Kyunghyun Cho, Douwe Kiela

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 ques- tions with decompositions is cumbersome, we take an unsupervised approach to pro- duce sub-questions, also enabling us to lever- age millions of questions from the internet.

arXiv preprint arXiv:2002.09758 · 2020

Finding Generalizable Evidence by Learning to Convince Q&A Models

Finding Generalizable Evidence by Learning to Convince Q&A Models

Ethan Perez, Siddharth Karamcheti, Rob Fergus, Jason Weston, Douwe Kiela, Kyunghyun Cho

We propose a system that finds the strongest supporting evidence for a given answer to a question, using passage-based question- answering (QA) as a testbed. We train evi- dence agents to select the passage sentences that most convince a pretrained QA model of a given answer, if the QA model received those sentences instead of the full passage.

arXiv preprint arXiv:1909.05863 · 2019

ELI5: Long Form Question Answering

ELI5: Long Form Question Answering

Angela Fan, Yacine Jernite, Ethan Perez, David Grangier, Jason Weston, Michael Auli

We introduce the first large-scale corpus for long-form question answering, a task requir- ing elaborate and in-depth answers to open- ended questions. The dataset comprises 270K threads from the Reddit forum “Explain Like I’m Five” (ELI5) where an online community provides answers to questions which are com- prehensible by five year olds. Compared to ex- isting datasets, ELI5 comprises diverse ques- tions requiring multi-sentence answers.

arXiv preprint arXiv:1907.09190 · 2019

Feature-wise transformations

Feature-wise transformations

Vincent Dumoulin, Ethan Perez, Nathan Schucher, Florian Strub, Harm de Vries, Aaron Courville, Yoshua Bengio

A survey showing how a simple family of conditioning mechanisms — scaling and shifting a network’s features based on an auxiliary input — recurs across a surprising range of neural network architectures and problem domains.

Distill · 2018

Visual Reasoning with Multi-hop Feature Modulation

Visual Reasoning with Multi-hop Feature Modulation

Florian Strub, Mathieu Seurin, Ethan Perez, Philippe Preux, Aaron Courville, Olivier Pietquin

Recent breakthroughs in computer vision and natural lan- guage processing have spurred interest in challenging multi-modal tasks such as visual question-answering and visual dialogue. For such tasks, one successful approach is to condition image-based convolutional network computation on language via Feature-wise Linear Modulation (FiLM) layers, i.e., per-channel scaling and shifting.

arXiv preprint arXiv:1808.04446 · 2018

FiLM: Visual Reasoning with a General Conditioning Layer

FiLM: Visual Reasoning with a General Conditioning Layer

Ethan Perez, Florian Strub, Vincent Dumoulin, Aaron Courville, CRIStAL France

We introduce a general-purpose conditioning method for neu- ral networks called FiLM : F eature-w i se L inear M odulation. FiLM layers influence neural network computation via a sim- ple, feature-wise affine transformation based on conditioning information.

arXiv preprint arXiv:1709.07871 · 2017

HoME: a Household Multimodal Environment

HoME: a Household Multimodal Environment

Simon Brodeur, Ethan Perez, Ankesh Anand, Florian Golemo, Luca Celotti, Florian Strub, et al.

We introduce HoME: a Ho usehold M ultimodal E nvironment for artificial agents to learn from vision, audio, semantics, physics, and interaction with objects and other agents, all within a realistic context. HoME integrates over 45,000 diverse 3D house layouts based on the SUNCG dataset, a scale which may facilitate learning, generalization, and transfer.

arXiv preprint arXiv:1711.11017 · 2017

Learning Visual Reasoning Without Strong Priors

Ethan Perez, Florian Strub, Vincent Dumoulin, Aaron Courville, CRIStAL France

Achieving artificial visual reasoning — the ability to answer image-related questions which require a multi-step, high-level process — is an important step towards artificial general intel- ligence. This multi-modal task requires learning a question- dependent, structured reasoning process over images from lan- guage.

arXiv preprint arXiv:1707.03017 · 2017

A dataset of rated conceptual arguments

Emery Cooper, Caspar Oesterheld, Linh Chi Nguyen, Alexander Kastner, Ethan Perez

Introduces a dataset aimed at improving how language models reason about open-ended conceptual questions, part of a broader effort to make AI more useful for navigating the risks of its own development.

Preprint · 2025

Generate-Feedback-Refine: How Much Does Model Quality in Each Role Matter?

Xiang Pan, Jason Phang, Guy Davidson, Ethan Perez

Studies how effectively language models can give and act on feedback to refine code, testing whether weaker models can meaningfully help stronger ones improve — a possible building block for scalable oversight.

ICLR 2025 Workshop on Deep Learning for Code · 2025

Plan B: Training LLMs to fail less severely

Julian Stastny, Niels Warncke, Dylan Xu, Aengus Lynch, Fazl Barez, Henry Sleight, Ethan Perez

Proposes a second line of defense for LLM safety: alongside trying to prevent harmful responses outright, train models so that when safeguards do fail, the resulting harm is reduced in severity.

Preprint · 2025

Simple probes can catch sleeper agents

Monte MacDiarmid, Timothy Maxwell, Nicholas Schiefer, Jesse Mu, Jared Kaplan, David Duvenaud, et al.

An early-stage follow-up to the Sleeper Agents paper, showing that simple linear probes on a model’s internal activations can reliably flag when a backdoored model is about to defect.

Anthropic Alignment Science blog · 2024