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Osbert Bastani

70 accepted papers

2026

Autonomous Play with Correspondence-Driven Trajectory Warping

ICLR 2026poster

The ability to conduct and learn from self-directed interaction and experience is a central challenge in robotics, offering a scalable alternative to labor-intensive human demonstrations. However, realizing such "play" requires (1) a policy robust to diverse, potentially out-of-distribution environm…

Cited by 0SourcecodeScholar
2026

Conformal Constrained Policy Optimization for Cost-Effective LLM Agents

AAAI 2026technical

While large language models (LLMs) have recently made tremendous progress towards solving challenging AI problems, they have done so at increasingly steep computational and API costs. We propose a novel strategy where we combine multiple LLM models with varying cost/accuracy tradeoffs in an agentic

Cited by 0SourcePDFScholar
2026

Divide and Abstract: Autoformalization via Decomposition and Abstraction Learning

ICLR 2026poster

Autoformalization, the task of translating informal mathematics into formal machine-verifiable languages, has long been challenging, even for individual statements. Beyond the statement level, mathematicians invest substantial effort in formalizing reusable abstractions such as common definitions an…

Cited by 0SourceScholar
2026

Knowledgeable Language Models as Black-Box Optimizers for Personalized Medicine

ICLR 2026poster

The goal of personalized medicine is to discover a treatment regimen that optimizes a patient's clinical outcome based on their personal genetic and environmental factors. However, candidate treatments cannot be arbitrarily administered to the patient to assess their efficacy; we often instead have…

Cited by 0SourceScholar
2026

Position: The Case for Theory-Level Autoformalization

ICML 2026spotlight

Autoformalization, translating informal natural language into formal, machine-verifiable languages, has been framed as a tool to generate training data for neural theorem provers, with most work focusing on individual statements. This position paper argues for theory-level autoformalization: formali…

Cited by 0SourceScholar
2026

Scaling Multi-Task Bayesian Optimization with Large Language Models

ICLR 2026poster

In multi-task Bayesian optimization, the goal is to leverage experience from optimizing existing tasks to improve the efficiency of optimizing new ones. While approaches using multi-task Gaussian processes or deep kernel transfer exist, the performance improvement is marginal when scaling beyond a m…

Cited by 0SourcecodeScholar
2026

Sparling: End-to-End Spatial Concept Learning via Extremely Sparse Activations

ICLR 2026poster

Real-world processes often contain intermediate state that can be modeled as an extremely sparse activation tensor. In this work, we analyze the identifiability of such sparse and local latent intermediate variables, which we call motifs. We prove our Motif Identifiability Theorem, stating that unde…

Cited by 0SourceScholar
2025

Alignment of Large Language Models with Constrained Learning

NeurIPS 2025poster

We study the problem of computing an optimal large language model (LLM) policy for the constrained alignment problem, where the goal is to maximize a primary reward objective while satisfying constraints on secondary utilities. Despite the popularity of Lagrangian-based LLM policy search in constrai…

Cited by 0SourceScholar
2025

Diversity By Design: Leveraging Distribution Matching for Offline Model-Based Optimization

ICML 2025poster

The goal of offline model-based optimization (MBO) is to propose new designs that maximize a reward function given only an offline dataset. However, an important desiderata is to also propose a *diverse* set of final candidates that capture many optimal and near-optimal design configurations. We pro…

2025

Vision Language Models are In-Context Value Learners

ICLR 2025spotlight

Predicting temporal progress from visual trajectories is important for intelligent robots that can learn, adapt, and improve. However, learning such progress estimator, or temporal value function, across different tasks and domains requires both a large amount of diverse data and methods which can s…

Cited by 2SourcePDFScholar
2025

Zeroth-Order Fine-Tuning of LLMs with Transferable Static Sparsity

ICLR 2025poster

Zeroth-order optimization (ZO) is a memory-efficient strategy for fine-tuning Large Language Models using only forward passes. However, applying ZO fine-tuning in memory-constrained settings such as mobile phones and laptops remains challenging since these settings often involve weight quantization,…

Cited by 0SourcePDFScholar
2024

DROID: A Large-Scale In-The-Wild Robot Manipulation Dataset

RSS 2024poster

The creation of large, diverse, high-quality robot manipulation datasets is an important stepping stone on the path toward more capable and robust robotic manipulation policies. However, creating such datasets is challenging: collecting robot manipulation data in diverse environments poses logistica…

Cited by 216SourcePDFScholar
2024

DrEureka: Language Model Guided Sim-To-Real Transfer

RSS 2024poster

Transferring policies learned in simulation to the real world is a promising strategy for acquiring robot skills at scale. However, sim-to-real approaches typically rely on manual design and tuning of the task reward function as well as the simulation physics parameters, rendering the process slow a…

Cited by 104SourcePDFScholar
2024

Environment Curriculum Generation via Large Language Models

CoRL 2024poster

Recent work has demonstrated that a promising strategy for teaching robots a wide range of complex skills is by training them on a curriculum of progressively more challenging environments. However, developing an effective curriculum of environment distributions currently requires significant expert…

Cited by 4SourceScholar
2024

Eureka: Human-Level Reward Design via Coding Large Language Models

ICLR 2024poster

Large Language Models (LLMs) have excelled as high-level semantic planners for sequential decision-making tasks. However, harnessing them to learn complex low-level manipulation tasks, such as dexterous pen spinning, remains an open problem. We bridge this fundamental gap and present Eureka, a human…

2024

Generative Adversarial Model-Based Optimization via Source Critic Regularization

NeurIPS 2024poster

Offline model-based optimization seeks to optimize against a learned surrogate model without querying the true oracle objective function during optimization. Such tasks are commonly encountered in protein design, robotics, and clinical medicine where evaluating the oracle function is prohibitively e…

2024

Learning Performance-Improving Code Edits

ICLR 2024spotlight

With the decline of Moore's law, optimizing program performance has become a major focus of software research. However, high-level optimizations such as API and algorithm changes remain elusive due to the difficulty of understanding the semantics of code. Simultaneously, pretrained large language mo…

2024

One-Shot Safety Alignment for Large Language Models via Optimal Dualization

NeurIPS 2024spotlight

The growing safety concerns surrounding large language models raise an urgent need to align them with diverse human preferences to simultaneously enhance their helpfulness and safety. A promising approach is to enforce safety constraints through Reinforcement Learning from Human Feedback (RLHF). For…

2024

Open X-Embodiment: Robotic Learning Datasets and RT-X Models : Open X-Embodiment Collaboration

ICRA 2024

Large, high-capacity models trained on diverse datasets have shown remarkable successes on efficiently tackling downstream applications. In domains from NLP to Computer Vision, this has led to a consolidation of pretrained models, with general pretrained backbones serving as a starting point for man

Cited by 910SourcecodeScholar
2024

Open X-Embodiment: Robotic Learning Datasets and RT-X Models : Open X-Embodiment Collaboration0

ICRA 2024poster

Large, high-capacity models trained on diverse datasets have shown remarkable successes on efficiently tackling downstream applications. In domains from NLP to Computer Vision, this has led to a consolidation of pretrained models, with general pretrained backbones serving as a starting point for man…

Cited by 259SourcecodeScholar
2024

PAC Prediction Sets Under Label Shift

ICLR 2024poster

Prediction sets capture uncertainty by predicting sets of labels rather than individual labels, enabling downstream decisions to conservatively account for all plausible outcomes. Conformal inference algorithms construct prediction sets guaranteed to contain the true label with high probability. The…

2024

TRAQ: Trustworthy Retrieval Augmented Question Answering via Conformal Prediction

NAACL 2024long

When applied to open-domain question answering, large language models (LLMs) frequently generate incorrect responses based on made-up facts, which are called hallucinations. Retrieval augmented generation (RAG) is a promising strategy to avoid hallucinations, but it does not provide guarantees on it…

2024

Uncertainty in Language Models: Assessment through Rank-Calibration

EMNLP 2024main

Language Models (LMs) have shown promising performance in natural language generation. However, as LMs often generate incorrect or hallucinated responses, it is crucial to correctly quantify their uncertainty in responding to given inputs. In addition to verbalized confidence elicited via prompting,…

2024

Universal Visual Decomposer: Long-Horizon Manipulation Made Easy

ICRA 2024poster

Real-world robotic tasks stretch over extended horizons and encompass multiple stages. Learning long-horizon manipulation tasks, however, is a long-standing challenge, and demands decomposing the overarching task into several manageable subtasks to facilitate policy learning and generalization to un…

Cited by 21SourceScholar
2023

Angelic Patches for Improving Third-Party Object Detector Performance

CVPR 2023poster

Deep learning models have shown extreme vulnerability to simple perturbations and spatial transformations. In this work, we explore whether we can adopt the characteristics of adversarial attack methods to help improve perturbation robustness for object detection. We study a class of realistic objec…

2023

LIV: Language-Image Representations and Rewards for Robotic Control

ICML 2023poster

We present Language-Image Value learning (LIV), a unified objective for vision-language representation and reward learning from action-free videos with text annotations. Exploiting a novel connection between dual reinforcement learning and mutual information contrastive learning, the LIV objective t…

2023

Robust Subtask Learning for Compositional Generalization

ICML 2023poster

Compositional reinforcement learning is a promising approach for training policies to perform complex long-horizon tasks. Typically, a high-level task is decomposed into a sequence of subtasks and a separate policy is trained to perform each subtask. In this paper, we focus on the problem of trainin…

2023

Uniformly Conservative Exploration in Reinforcement Learning

AISTATS 2023poster

A key challenge to deploying reinforcement learning in practice is avoiding excessive (harmful) exploration in individual episodes. We propose a natural constraint on exploration—uniformly outperforming a conservative policy (adaptively estimated from all data observed thus far), up to a per-episode…

Cited by 6SourcePDFScholar
2023

VIP: Towards Universal Visual Reward and Representation via Value-Implicit Pre-Training

ICLR 2023top-25%

Reward and representation learning are two long-standing challenges for learning an expanding set of robot manipulation skills from sensory observations. Given the inherent cost and scarcity of in-domain, task-specific robot data, learning from large, diverse, offline human videos has emerged as a p…

2022

Conservative and Adaptive Penalty for Model-Based Safe Reinforcement Learning

AAAI 2022technical

Reinforcement Learning (RL) agents in the real world must satisfy safety constraints in addition to maximizing a reward objective. Model-based RL algorithms hold promise for reducing unsafe real-world actions: they may synthesize policies that obey all constraints using simulated samples from a lear…

2022

Counterfactual Explanations for Natural Language Interfaces

ACL 2022short

A key challenge facing natural language interfaces is enabling users to understand the capabilities of the underlying system. We propose a novel approach for generating explanations of a natural language interface based on semantic parsing. We focus on counterfactual explanations, which are post-hoc…

2022

Exploring with Sticky Mittens: Reinforcement Learning with Expert Interventions via Option Templates

CoRL 2022poster

Long horizon robot learning tasks with sparse rewards pose a significant challenge for current reinforcement learning algorithms. A key feature enabling humans to learn challenging control tasks is that they often receive expert intervention that enables them to understand the high-level structure o…

Cited by 4SourcecodeScholar
2022

Neurosymbolic Deep Generative Models for Sequence Data with Relational Constraints

NeurIPS 2022accept

There has been significant recent progress designing deep generative models that generate realistic sequence data such as text or music. Nevertheless, it remains difficult to incorporate high-level structure to guide the generative process, and many such models perform well on local coherence, but l…

Cited by 7SourcePDFScholar
2022

Offline Goal-Conditioned Reinforcement Learning via $f$-Advantage Regression

NeurIPS 2022accept

Offline goal-conditioned reinforcement learning (GCRL) promises general-purpose skill learning in the form of reaching diverse goals from purely offline datasets. We propose $\textbf{Go}$al-conditioned $f$-$\textbf{A}$dvantage $\textbf{R}$egression (GoFAR), a novel regression-based offline GCRL algo…

Cited by 33SourcePDFScholar
2022

Practical Adversarial Multivalid Conformal Prediction

NeurIPS 2022accept

We give a simple, generic conformal prediction method for sequential prediction that achieves target empirical coverage guarantees on adversarial data. It is computationally lightweight --- comparable to split conformal prediction --- but does not require having a held-out validation set, and so all…

2022

Regret Bounds for Risk-Sensitive Reinforcement Learning

NeurIPS 2022accept

In safety-critical applications of reinforcement learning such as healthcare and robotics, it is often desirable to optimize risk-sensitive objectives that account for tail outcomes rather than expected reward. We prove the first regret bounds for reinforcement learning under a general class of risk…

Cited by 23SourcePDFScholar
2022

Sequential Covariate Shift Detection Using Classifier Two-Sample Tests

ICML 2022spotlight

A standard assumption in supervised learning is that the training data and test data are from the same distribution. However, this assumption often fails to hold in practice, which can cause the learned model to perform poorly. We consider the problem of detecting covariate shift, where the covariat…

2022

Versatile Offline Imitation from Observations and Examples via Regularized State-Occupancy Matching

ICML 2022spotlight

We propose State Matching Offline DIstribution Correction Estimation (SMODICE), a novel and versatile regression-based offline imitation learning algorithm derived via state-occupancy matching. We show that the SMODICE objective admits a simple optimization procedure through an application of Fenche…

2021

Abstract Value Iteration for Hierarchical Reinforcement Learning

AISTATS 2021poster

We propose a novel hierarchical reinforcement learning framework for control with continuous state and action spaces. In our framework, the user specifies subgoal regions which are subsets of states; then, we (i) learn options that serve as transitions between these subgoal regions, and (ii) constru…

2021

Compositional Reinforcement Learning from Logical Specifications

NeurIPS 2021poster

We study the problem of learning control policies for complex tasks given by logical specifications. Recent approaches automatically generate a reward function from a given specification and use a suitable reinforcement learning algorithm to learn a policy that maximizes the expected reward. These a…

2021

Conservative Offline Distributional Reinforcement Learning

NeurIPS 2021poster

Many reinforcement learning (RL) problems in practice are offline, learning purely from observational data. A key challenge is how to ensure the learned policy is safe, which requires quantifying the risk associated with different actions. In the online setting, distributional RL algorithms do so by…

2021

Group-Sparse Matrix Factorization for Transfer Learning of Word Embeddings

ICML 2021spotlight

Sparse regression has recently been applied to enable transfer learning from very limited data. We study an extension of this approach to unsupervised learning—in particular, learning word embeddings from unstructured text corpora using low-rank matrix factorization. Intuitively, when transferring w…

2021

Likelihood-Based Diverse Sampling for Trajectory Forecasting

ICCV 2021poster

Forecasting complex vehicle and pedestrian multi-modal distributions requires powerful probabilistic approaches. Normalizing flows (NF) have recently emerged as an attractive tool to model such distributions. However, a key drawback is that independent samples drawn from a flow model often do not ad…

Cited by 33PDFcodeScholar
2021

Program Synthesis Guided Reinforcement Learning for Partially Observed Environments

NeurIPS 2021spotlight

A key challenge for reinforcement learning is solving long-horizon planning problems. Recent work has leveraged programs to guide reinforcement learning in these settings. However, these approaches impose a high manual burden on the user since they must provide a guiding program for every new task.…

2020

Calibrated Prediction with Covariate Shift via Unsupervised Domain Adaptation

AISTATS 2020poster

Reliable uncertainty estimates are an important tool for helping autonomous agents or human decision makers understand and lever-age predictive models. However, existing approaches to estimating uncertainty largely ignore the possibility of covariate shift—i.e.,where the real-world data distribution…

Cited by 68SourcePDFScholar
2020

Generating Programmatic Referring Expressions via Program Synthesis

ICML 2020poster

Incorporating symbolic reasoning into machine learning algorithms is a promising approach to improve performance on learning tasks that require logical reasoning. We study the problem of generating a programmatic variant of referring expressions that we call referring relational programs. In particu…

2020

Neurosymbolic Transformers for Multi-Agent Communication

NeurIPS 2020poster

We study the problem of inferring communication structures that can solve cooperative multi-agent planning problems while minimizing the amount of communication. We quantify the amount of communication as the maximum degree of the communication graph; this metric captures settings where agents have…

2020

PAC Confidence Sets for Deep Neural Networks via Calibrated Prediction

ICLR 2020poster

We propose an algorithm combining calibrated prediction and generalization bounds from learning theory to construct confidence sets for deep neural networks with PAC guarantees---i.e., the confidence set for a given input contains the true label with high probability. We demonstrate how our approach…

Cited by 76SourcecodeScholar
2020

Synthesizing Programmatic Policies that Inductively Generalize

ICLR 2020poster

Deep reinforcement learning has successfully solved a number of challenging control tasks. However, learned policies typically have difficulty generalizing to novel environments. We propose an algorithm for learning programmatic state machine policies that can capture repeating behaviors. By doing s…

Cited by 62SourceScholar
2019

A Composable Specification Language for Reinforcement Learning Tasks

NeurIPS 2019poster

Reinforcement learning is a promising approach for learning control policies for robot tasks. However, specifying complex tasks (e.g., with multiple objectives and safety constraints) can be challenging, since the user must design a reward function that encodes the entire task. Furthermore, the user…

2019

Learning Safe Unlabeled Multi-Robot Planning with Motion Constraints

IROS 2019poster

In this paper, we present a learning approach to goal assignment and trajectory planning for unlabeled robots operating in 2D, obstacle-filled workspaces. More specifically, we tackle the unlabeled multi-robot motion planning problem with motion constraints as a multi-agent reinforcement learning pr…

Cited by 41SourceScholar
2016

Measuring Neural Net Robustness with Constraints

NeurIPS 2016poster

Despite having high accuracy, neural nets have been shown to be susceptible to adversarial examples, where a small perturbation to an input can cause it to become mislabeled. We propose metrics for measuring the robustness of a neural net and devise a novel algorithm for approximating these metrics…

Cited by 554SourcePDFScholar