Juan Carlos Niebles


2025

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LATTE: Learning to Think with Vision Specialists
Zixian Ma | Jianguo Zhang | Zhiwei Liu | Jieyu Zhang | Juntao Tan | Manli Shu | Juan Carlos Niebles | Shelby Heinecke | Huan Wang | Caiming Xiong | Ranjay Krishna | Silvio Savarese
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing

While open-source vision-language models perform well on simple question-answering, they still struggle with complex questions that require both perceptual and reasoning capabilities. We propose LATTE, a family of vision-language models that have LeArned to Think wiTh vision spEcialists. By offloading perception to state-of-the-art vision models, our approach enables vision-language models to focus solely on reasoning over high-quality perceptual information. To train LATTE, we synthesize and filter a large dataset of 293K multi-modal reasoning traces over perceptual outputs of vision specialists. LATTE trained on this data achieves significant 4-5% gains over baselines across 6 benchmarks covering both perception and reasoning abilities. Ablation studies reveal that the effectiveness of multi-modal reasoning traces depends on the data sources, formats, and quality of thoughts.

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ActionStudio: A Lightweight Framework for Data and Training of Large Action Models
Jianguo Zhang | Thai Quoc Hoang | Ming Zhu | Zuxin Liu | Shiyu Wang | Tulika Manoj Awalgaonkar | Akshara Prabhakar | Haolin Chen | Weiran Yao | Zhiwei Liu | Juntao Tan | Juan Carlos Niebles | Shelby Heinecke | Huan Wang | Silvio Savarese | Caiming Xiong
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing

Large Action models are essential for enabling autonomous agents to perform complex tasks. However, training such models remains challenging due to the diversity of agent environments and the complexity of noisy agentic data. Existing infrastructure offers limited support for scalable, agent-specific fine-tuning and standardized agent data processing. We introduce ActionStudio, a lightweight and extensible data and training framework designed for large action models. ActionStudio unifies diverse agent trajectories using our proposed Unified Format 2.0, supports a range of training workflows with optimized multi-node distributed setup, and integrates robust preprocessing and real-time verification tools. ActionStudio demonstrates up to 9× higher throughput compared to existing agentic training frameworks, and our trained models yield top performances across public and realistic agent benchmarks. To support the broader research community, we open-source the ActionStudio framework and release actionstudio-98k, a curated dataset of 98k high-quality trajectories.

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Contra4: Evaluating Contrastive Cross-Modal Reasoning in Audio, Video, Image, and 3D
Artemis Panagopoulou | Le Xue | Honglu Zhou | Silvio Savarese | Ran Xu | Caiming Xiong | Chris Callison-Burch | Mark Yatskar | Juan Carlos Niebles
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing

Real-world decision-making often begins with identifying which modality contains the most relevant information for a given query. While recent multimodal models have made impressive progress in processing diverse inputs, it remains unclear whether they can reason contrastively across multiple modalities to select the one that best satisfies a natural language prompt. We argue this capability is foundational, especially in retrieval-augmented and decision-time contexts, where systems must evaluate multiple signals and identify which one conveys the relevant information. To evaluate this skill, we introduce Contra4, a dataset for contrastive cross-modal reasoning across four modalities: image, audio, video, and 3D. Each example presents a natural language question alongside multiple candidate modality instances, and the model must select the one that semantically aligns with the prompt. Contra4 combines human-annotated captions with a mixture-of-models round-trip-consistency filter to ensure high-quality supervision, resulting in 174k training examples and a manually verified test set of 2.3k samples. While task-specific fine-tuning improves performance by 56% relative to baseline, state-of-the-art models still achieve only 56% accuracy overall and 42% in four-modality settings, underscoring a significant limitation in current multimodal models.

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LAM SIMULATOR: Advancing Data Generation for Large Action Model Training via Online Exploration and Trajectory Feedback
Thai Quoc Hoang | Kung-Hsiang Huang | Shirley Kokane | Jianguo Zhang | Zuxin Liu | Ming Zhu | Jake Grigsby | Tian Lan | Michael S Ryoo | Chien-Sheng Wu | Shelby Heinecke | Huan Wang | Silvio Savarese | Caiming Xiong | Juan Carlos Niebles
Findings of the Association for Computational Linguistics: ACL 2025

Large Action Models (LAMs) for AI Agents offer incredible potential but face challenges due to the need for high-quality training data, especially for multi-steps tasks that involve planning, executing tool calls, and responding to feedback. To address these issues, we present LAM SIMULATOR, a comprehensive framework designed for online exploration of agentic tasks with high-quality feedback. Our framework features a dynamic task query generator, an extensive collection of tools, and an interactive environment where Large Language Model (LLM) Agents can call tools and receive real-time feedback. This setup enables LLM Agents to explore and solve tasks autonomously, facilitating the discovery of multiple approaches to tackle any given task. The resulting action trajectory data are then used to create high-quality training datasets for LAMs. Our experiments on popular agentic benchmarks, ToolBench and CRMArena, highlight the effectiveness of LAM SIMULATOR: models trained with self-generated datasets using our framework achieve significant performance gains, up to a 49.3% improvement over their original baselines. LAM SIMULATOR requires minimal human input during dataset creation, highlighting LAM SIMULATOR’s efficiency and effectiveness in speeding up development of AI agents.

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xLAM: A Family of Large Action Models to Empower AI Agent Systems
Jianguo Zhang | Tian Lan | Ming Zhu | Zuxin Liu | Thai Quoc Hoang | Shirley Kokane | Weiran Yao | Juntao Tan | Akshara Prabhakar | Haolin Chen | Zhiwei Liu | Yihao Feng | Tulika Manoj Awalgaonkar | Rithesh R N | Zeyuan Chen | Ran Xu | Juan Carlos Niebles | Shelby Heinecke | Huan Wang | Silvio Savarese | Caiming Xiong
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)

Autonomous agents powered by large language models (LLMs) have attracted significant research interest. However, the open-source community faces many challenges in developing specialized models for agent tasks, driven by the scarcity of high-quality agent datasets and the absence of standard protocols in this area. We introduce xLAM, a series of large action models designed for AI agent tasks. The xLAM series includes five models with both dense and mixture-of-expert architectures, ranging from 1B to 8x22B parameters, trained using a scalable, flexible pipeline that unifies, augments, and synthesizes diverse datasets to enhance AI agents’ generalizability and performance across varied environments. Our experimental results demonstrate that xLAM consistently delivers exceptional performance across multiple agent ability benchmarks, notably securing the 1st position on the Berkeley Function-Calling Leaderboard, outperforming GPT-4, Claude-3, and many other models in terms of tool use. By releasing the xLAM series, we aim to advance the performance of open-source LLMs for autonomous AI agents, potentially accelerating progress and democratizing access to high-performance models for agent tasks.

2024

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PRACT: Optimizing Principled Reasoning and Acting of LLM Agent
Zhiwei Liu | Weiran Yao | Jianguo Zhang | Zuxin Liu | Liangwei Yang | Rithesh R N | Tian Lan | Ming Zhu | Juntao Tan | Shirley Kokane | Thai Quoc Hoang | Juan Carlos Niebles | Shelby Heinecke | Huan Wang | Silvio Savarese | Caiming Xiong
Proceedings of the 28th Conference on Computational Natural Language Learning

We introduce the Principled Reasoning and Acting (PRAct) framework, a novel method for learning and enforcing action principles from trajectory data. Central to our approach is the use of text gradients from a reflection and optimization engine to derive these action principles. To adapt action principles to specific task requirements, we propose a new optimization framework, Reflective Principle Optimization (RPO). After execution, RPO employs a reflector to critique current action principles and an optimizer to update them accordingly.We investigate the RPO framework under two scenarios: Reward-RPO, which uses environmental rewards for reflection, and Self-RPO, which conducts self-reflection without external rewards. Additionally, we developed two RPO methods, RPO-Traj and RPO-Batch, to adapt to different settings.Experimental results across four environments demonstrate that the PRAct agent, leveraging the RPO framework, can effectively learn and apply action principles to enhance performance.

2018

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Translating Navigation Instructions in Natural Language to a High-Level Plan for Behavioral Robot Navigation
Xiaoxue Zang | Ashwini Pokle | Marynel Vázquez | Kevin Chen | Juan Carlos Niebles | Alvaro Soto | Silvio Savarese
Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing

We propose an end-to-end deep learning model for translating free-form natural language instructions to a high-level plan for behavioral robot navigation. We use attention models to connect information from both the user instructions and a topological representation of the environment. We evaluate our model’s performance on a new dataset containing 10,050 pairs of navigation instructions. Our model significantly outperforms baseline approaches. Furthermore, our results suggest that it is possible to leverage the environment map as a relevant knowledge base to facilitate the translation of free-form navigational instruction.